Well that actually wouldn't be that hard to do, getting stuff as right as possible as the engine allows.
The main change I'd that needs to be done is have the GE start out (in pre-ANH campaigns at least) with the full Grand Army of the Republic tech tree.
If you do 18 BBY. it'd be starting while the Empire is a year old.
If 20BBY, it'd be starting in the middle of the clone wars (which would add new issues and make this way too much work for you).
Doesn't the GE already sort of have the full Grand Army of the Republic tech tree? Or anything you miss from it?
Thing is that I would love to start the mod at 20 BBY. But you're right, there's some issues then with how to portray the CIS, early Rebellion and all the ships of that time. Anyway, next version start date is changed to 18 BBY.
Basically all I propose is take what actually existed in the timeline at that period of time, and give it to the Empire.
For the Rebels, give them pre-war Republic tech within reason mixed with some sepritist tech, all buildible at the start of the campaign.
For the Imps, the republic gear would obviously phase out as you research new ships, and for the Rebels it'd phase out as they gain shipyards and the ability to construct vessels from scratch, rather than upgrading whatever they can get.
I will try to get everything buildable that existed at the time for the Empire and then have it phase out with upgrades. In my opinion, the rebel tech should be CR90's, Dreadnaughts and Recusant Mark II's as the early ships (as well as Z-95, R41's and Y-wings). Rest have to get researched. If I ever add completely new units, the Rebel cause will see more early units. One ship that would be nice to get into the mix would be the Providence-class.
One big change from stock PR I'd have to recomend is removing rockets from the Y-Wings until prehaps their final upgrade, as the rocket payload actually makes the Y-Wing's supperior (I think at least) to the B-Wing until it's mostly upgraded, at least as far as a pure bomber role goes, due to Torpedoes penetrating sheilds.
Remember that I could also just make the B-wing have heavy rockets in earlier upgrades. Due to how much B-wing upgrades cost it will still stay balanced
Thanks for bringing this up however! Any feedback like this really helps and saves me time in testing stuff myself!
If you can edit shield penetrating weapons in PR (Torps, missles, slugthrowers, and disruptors, etc.) to not penetrate shields, it would go a far ways towards resolving that particular issue (some of the PR staff have said a change is coming in that direction, if nothing else that'd be a way to test this out).
There are none or very little slugthrowers and disruptors in space combat in my sub mod. This might change at some point however. But as P.O._210877 said, it's canonical for them to penetrate shields.
Torpedoes and missiles is another issue. It is very unlikely that I will stop them from penetrating, but it is possible there will be changes to how strong some torpedoes/rockets are or changes to hull strength on some ships.
For ISD/VSD upgrades, also, I'd have to recomend that instead of simply upgrading between the four versions currently ingame you add intermediary upgrades.
As for the actual changes I recomend, as an example I'll start out with the ISD.
Note: ALL upgrades (or new ship research) that involves new ships in the compliment should (if possible in this engine) be set to not be researchable until you've researched (and upgraded) to all of the models the ship has in it's compliment.
-Start it out as the Imperator class star destroyer, since that was the name for the ship in the Republic Navy. Wookiepedia lists it as introduced in 22 BBY, so no reason for the Empire to not start with these based on your starting dates, since it's a republic vessel.
Compliment: Republic era vessels. ARC-170's as bombers/attack ships. The early T.I.E. fighters from the starting units in stock PR as the mainstay fighter. LAATs as transports/shuttles.
-From there, the first upgrade should be to Imperial Star Destroyer, prehaps keep ARC-170's in the bomber role
-Imperial Star Destroyer Mk1 upgrade. Brings the ship up to Imperial I class specs and compliment. Possibly have several upgrades for the Mk1 ISD, renaming to ISD Ia, Ib, etc.
-Imperial Star Destroyer Mk2. Brings the production lines up to the basic ISD II standard. Compliment should be TIE fighters/Bombers at the start, with a MkIIa model having TIE Interceptors added. Wookiepedia lists the ISD II as debuting in 0ABY.
--Imperial Star Destroyer Mk3/4 upgrades: these should be (I think) just upgraded ISD I's and IIs with better stats and heavier compliment/broadside. Mk3/4's should also include better defensive weapons geared against snubcraft.
Mostly, I'm going to have to just suggest splitting the VSD into TWO lines of ships.
The Mk1 VSD should be avalible to the Imps from the start, upgradable, and retain it's missile payload. Speed for a fully upgraded Ml1 VSD should be on par with a MC-40, 5-10 slower.
The Mk2 VSD and beyond should however be treated as a variant model with a payload that focuses on guns rather than missiles, with a mix of turbolasers/ions as it's loadout.
Yes, at some point I will set it as a requirement for ship research to have the fighters in the complement researched. This will be for all ships however. These changes I hope will make the campaign a more canonical experience as the AI has to go through ships in the right order instead of just ignoring some research/upgrades and focusing on other research, making it end up with late models of one ship and the first model of another ship.
VSD and ISD will both have 5 versions (as it is already). But the first version of these ships will be better implemented. I wont have the Imperator in the mod as a CW era ship, but rather an early ISD. The complement will remain V-wings with possibly 1 squadron of ARC-170's added to the mix and one V-wing squadron removed, the price of the early ISD will remain high to balance it.
I like your ideas for additional variants of ISD's though (these wont be as many as you listed, but maybe a couple at some point), I would very much want to portray the Empire starting to upgrade ship complements with TIE Interceptors instead of TIE Fighters. This would mean that there's two ISD I's, one with 5 TIE Fighter squadrons (and the rest of the usual ISD complement), and one ISD I with a few TIE Interceptor squadrons instead (similar to the current ISD II complement).
VSD's will remain as they are for canonical reasons, but with 5 variants instead of 4. I also want to make as little unit variant additions as possible, as it heavily impacts performance. So new production lines when not really needed from a gameplay/canonical perspective are unlikely to happen
Anyway, thanks for your extensive feedback!