I actually can't say I've seen many call for Caufield to hit 50. 40 yes as he often gets comped to DeBrincat.
Romanov like Poehling the summer before got overhyped by Hab fans due to the WJC's. That said I think he should end up being a very solid NHLer but have had my questions about how much offensive upside he has.
KK though I do think he could end up better then Tkachuk or around that level, if he can get his skating, lower body strength improved enough over the next 2-3 years. It will also depend on who his wingers are as he's a playmaker that has a good shot but needs a good bit of work on it, needs to learn to get it off more quickly and to hit the net more.