Huh, that's a pretty interesting analysis. I'd never thought about the "actual" performance of the KV-2 with regards to AT, in comparison to its' ostensibly "intended" (and logical) performance.
DO you think it warrants any changes?
that's a good question, tbh. if you're taking the base performance as the benchmark, i'd say the kv-2 is quite a bit better than the is-2, considering it has comparable AT and much better AI capabilities. however, the is-2 scales much better with veterancy in terms of firepower as the kv-2 doesn't get the 30% reload bonus other heavies do. the extra 160 HP are nice for sure, but this is arguably not not as valuable as the ROF and range boost of the is-2.
hence, i think the better base performance together with worse scaling is a pretty good trade-off already and no changes are required imho. the kv-2 starts stronger, but comes a bit later than the is-2, which in turn has ample time to close the gap through veterancy (assuming it does require a CP less?).