On to the question: why did the design team choose to remove the CARRACK's tractor beam projectors?
Thanks for registering! As for your question, when I was researching the Carrack, I saw it sometimes listed as having tractor beams and sometimes not, so keeping them off the original was my way of retconning that discrepancy. The Carrack is an old and venerable design that probably launched around 40 BBY, so it's not unreasonable to expect it to have been upgraded by the Empire at
some point, even if the EU authors don't comprehend the universe well enough to assign a name to such an upgrade (I called it the Mark II for the sake of simplicity). I likewise used the Mark II upgrade to explain the canonical inconsistency in speed (68 MGLT from XWA and 80 MGLT from the top speed of a T-65B) and provide it with some additional shielding, since the RPGs seem to consider the Carrack to be tougher than the Nebulon-B, instead of it being the other way around as in XWA.
Considering the Carrack-Class has no hangar bays...tractor beams wouldn't be that necessary.
They're offensive tractor beams. I read somewhere (NEGWT, I believe) that most ships with hangars have some kind of tractor beams, but that they're not always powerful enough to be used in combat. The ones listed as armaments are. So it's kind of like particle shielding, I guess. But that's also from the same source that said seismic charges create "a temporary vacuum in space", so take it as you will.
I'm pretty sure the Carrack-class has a hangar bay with a squadron of four TIE Fighters.
Well, it has an external rack, but that probably wouldn't necessitate the addition of tractor beams.