The only things that need to change with these two, alongside every other heavy, is the rear armour should be lower. If you manage to get a flank off with even just a T-34/Sherman/P4/Bazookas, you should penetrate 100% of the time. Currently the rear armour on some of these monsters is so huge that you bounce shots point black with rear armour, which is silly. It's already far too risky to flank given the accessibility of Shreks, AT Guns and Snares that a Flank should be even more rewarded.
If they get some more offensive buff then this +1000