The rocket is definitely a great end-game ability. Probably one of the best.
While saying it takes out 90% of the health isn't how I remember it, a full on strafe from front to back versus large hitbox tanks means you could get as many as 6 rockets (3 set times 2) in. As far as I know, that means you can knock out at least half a health bar using a ram + strafe combo. Not enough to be a no-brainer delete, but if your tank is caught out in a bad spot, it won't take much more to finish it off.
I don't know what's a good move for tweaking this. It's a pretty expensive combo if you fail, after all. The t-34 is usually dead as a cost, and the rockets are not cheap on ammo. Maybe reduce rocket stafe cost back to pre-nerf and reduce frequency of rockets fired during stafe?
The rockets is always comes from rear armor, and Heavy Tanks always cant react to evade that ram + rockets.
My tanks or my teammate tanks, is not out of positions, the t34 just charge ahead and other followed. afaik and experience, i never see this tactic fail to delete a tank in a game