This mod is not RA2/YR, and the point of making units less effective against certain targets was to prevent One-Unit-To-Win-Them-All scenarios (although i guess one could argue that certain units for certain factions still fall into that role). I also disagree on basic infantry being bad, they are used thorough the entire game in multiplayer, unlike RA2/YR. Especially anti-tank/air infantry. Only Soviets tend to have "bad infantry" problems.
If you want to know what is good against what kind of target, unit profiles on MO web page roughly (although not perfectly) provides that information.
Are you talking the advanced infantry or the basic infantry? Because the basic infantry (esp soviets) are nigh unusable. Regarding the one unit to win them all scenario, pretty much any unit could be used to win a mission in red alert 2/YR, that is not the case in this game. Units in general feel far weaker and less effective on the whole. They go from trading poorly to trading at a massive negative exponent. It's bad enough that it can even bug the AI with how little units do, causing them to spaz out trying to attack too many units at once. It's just a bit much. Most units tend to only be effective against one other type of unit, and then they load foam darts versus everything else. It's on the whole not a very satisifying experience watching a tank and an infantry impotently fire foam at each other for a solid minute till one of them dies.
Red Alert 2/Yuri's Revenge at least had a dynamic where most units were fairly effective against most other types of units, with a handful of bad matchups which they performed below par, but not harshly so. It was a game of soft counters, versus the current game of hard counters. I've seen the game compared to Starcraft, of all things, despite how in starcraft even the basic units you produce are still able to kill any other unit they attack, they don't impotently smack them for fractional damage.