Hmm, good point about the panzer ii. I ought to have gotten it with panzerschreck support. When would you throw grenades though? I like my nades.
I usually only throw grenades opportunistically. I throw one if I'm certain it can't be dodged in time. I would also throw it at a unit in cover or a building that will either be forced to move or eat the blast, which is a win/win with either result being a success. If you can't put yourself in a situation where the grenade toss has only positive outcomes for you, you're gambling with your munitions resource and hoping for a payout.
Grenades are fine when they work, but it's important to consider the cost. Grenades aren't free, and sometimes that's easy to forget. Habitually throwing grenades gets predictable as well, since your opponent will come to expect it. It's a trick that generally works less well with each use.
That was me looking back on how you could've improved your infantry force. I saw that you needed some infantry-held AT weapons to counter the SU-85s, but you couldn't afford them.
I think turbo had a good point when he said a win is a win. If you're looking for more efficiency it's important to nitpick your decisions to try and eliminate faults. It's the little things that can often make a huge difference when you consider how they affect other parts of your strategy.