I'm separating my two main issues to keep the threads clean.
Ok, so my Mato tank, I bought the Mato metal tracks with the duck bill like extensions on them. Also purchased the full metal VVSS suspension and drive wheels.
So all that installed nicely and adds a nice bit of weight to the tank, the tracks if I recall had like 77 links. The tank when moving now moves straight, but throws a track when turning. In stock form with plastic suspension it went straight and turned fine.
Step 1: I removed one link down to 76. Put that back on. Tank now turns without throwing a track but the track tension is a bit too tight with the tighter spring rate on the metal suspension. And it veers right when moving forward.
Step 2: I take all the suspension apart, compress each spring in a vice for a few seconds. This reduces the spring rate very slightly and softens the springs, when fully assembled the tank now actually floats on the suspension vs being fully propped up on the fully extended springs. The tank now sits more like a real Sherman would judging from pics I've seen of them stationary in fields. The added bonus, was now the track tension seemed perfect. Only one problem, the tank still veers slightly right. I went back to 77 links but knew that would not work after the spring rate mods, it did drive straight again but threw a track when turning.
Step 3: I throw a minor tantrum

So not sure what to do, I can probably live with it moving right and just correct every so often but I'd much prefer a tank that goes straight when I tell it to. Or it becomes an expensive burned-out smoking hulk on the battle field.
Thanks all!