Comintern as a doctrine was always best in the very early game.
No wonder, considering people start with non-armored units and heavy armor is only available later in the game.
Rocket artillery was in that case main Comintern early focus. Or rather any faction focus if you wanted to remove enemy units quickly and from range. Comintern however did have access to them early.
I feel like research being longer, as well as production times does make sense if the goal is to make other unit types also have a valid fight-back chance in the very early stage of the game.
EDIT: Besides, the damage went from 3.8 to 3.5 per attack.
0.3 damage, but... only on the first level unit. Level 2 and 3 were untouched.
Production times are more important, making it harder to just spam it.
Good balance for the early game.
Doesn't really affect the end-game.
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On the other side, we have buffs to medium tank, upkeep costs etc.
Those things usually matter more when it comes to the late game.
Upkeep will matter more when you have more units, but new provinces only give you 25% of what starting ones do after all.
Does it give the fighting chance it needed to start winning in long public matches?
It might help it. But doesn't necessarily guarantee it.
Comintern lacks on terms of airforce. With penalties both to fighters as well as SP Anti-air.
So when the game starts turning into long-frontline battles, with a lot of planes flying to support... it's gonna be problematic.
To sum up:
Comintern will stay what it is - a doctrine which main task is to get your advantage early and then steamroll everyone.
It will have bit harder time to do this. It might have bit easier time in the endgame even if they don't do this.
So in general I would say it makes this faction bit less "swingy" and balanced.
Not balanced in terms of comparison with other factions, but rather in balance with itself.