No, not that late. I don't play long games often. much earlier than that, and shortly after T4 is unlocked. There's the choice between sherman or jacksons. It's kind of either-or sort of deal. 1 jackson and 1 sherman isn't effective. I find the choice limiting as one is strong AI, below average AT and the other is strong AT, zero AI. The M8 I get even later on and I often don't get a chance to at that... not enough fuel.
thats not too late,at least by my standards
Which one you pick depends on how the game is going
I almost always pick 2 shermans then jackson,just one sherman can take on a P4 with a bit of RNG or a flank,and one can even stand up to an a OKW panther if you have zooks and AT gun support. People underrate the AT ability of a sherman,its more than capable of taking ANYTHING on,if it has some help,and can flank of course.
2 Shermans,if given a chance to flank,can WRECK any tank either german faction can put out by the 20-25 min mark.
Then at that point if you havent lost either sherman,you can get a jackson,which is a rather nasty threesome.
However,if im not feeling like i have the initiative fuelwise,ill get the jackson first,since obviously its better 1v1 vs most german tanks itll face at that time,without requiring luck or a flank.