I would suggest you start smaller & learn some tactics.
Yes Bradleys need flank shots to kill T-90s a lot of stuff does, could be why they built them
Abrams infantry & some transport to get them around are quite capable of dealing with but not an easy fight. If your tanks cant cut it use them to snipe or hit & run strip infantry support from tanks first then kill them.
The timeframe you are talking about Russian stuff is not cheap they have some very expensive stuff to. Troops APCs etc that cost more than yours