Yeah I think there will be some regression but some of it will be good.
Varsho was actually not that great in LF for some reason. I bet that corrects itself and you could see better defensive numbers from him. Regardless of the numbers though, he's in his prime and should carry on.
My guess is that Vlad is A LOT better. Not because I think he is good. But his metrics were bordering on unplayable last year at -13 OAA. The other 3 years he played 1st he was -2, -3, and -3. If he merely gets back to -3 that alone could make up for regression we get from older guys like KK and Springer or the drop in talent from Whit to Schneider (which is really the only clear drop-off that we'll have).