Yes, I agree. As I said in the previous post- fish don't fold enough. Especially 52/14 one. He will not raise every other hand, so once he does, he will have a very hard time folding.
That's why I suggest you go with your value range vs him. 15bigs deep in you are in no hurry and you certainly don't wanna take A7o vs QJs type of flips.
The gap between reg's opening and calling range is what matters the most. It's a sensitive area and only little changes might make a big difference to our ranges. My re-steal range vs a reg who steals 20% BTN and calls 88+, AJo+ will be much tighter than a reg that steal 35% and calls 88+, AJo.
I expect a good reg to be raising the BTN quite a bit, so any pair, any suited ace, strong offsuited aces, mid suited kings, strong broadway+ mid suited connectors and gappers+ some suited face card hands that have flush and straight possibility such as J9s or Q8s to be a good starting point. However, we might have to adjust if he starts calling us lite or has seen us pushing lite. A lot of factors play role here. 15bb is perfect for re-stealing imo. However, things might change up pretty quickly depending on who's in the blinds, eff. stack sizes, previous history and so on.
Basically, once again. Vs fish, we mostly re-steal strong value hands as they won't raise/fold enough ( especially 6-player SnG fish that are very loose). Vs regs, we can re-steal a lot of with blocker hands such as Ax, Kx etc. and also hands that good equity if called such as suited connectors and pairs.