The AK hand I want to stress two things.
Firstly it's close, the points you guys raise are valid, taking some initiative will force him off the best hand or a split sometimes.
Secondly, it's not a situation I'm going to worry about too much. AK in mid position vs a tight range just doesn't get me too excited.
AKo
vs 21/5
Surely the key statistic is that you only have 30 something hands on him.
So the only real conclusion you can make on the sample size - is that he is looseish and very passive. I think it is unlikely that he is positionally aware so his opening which might be strong is not really effected by his table position.
I agree, the most likely range you see here is 88+, AQ+.
If those above points are true.
Then surely there is more value in capitalising on our hand strength vs his range now, isolate with intiative and achieve more often than not what we want.
HU vs the fish IP with intiative and the top of our range.
If by value you mean making him fold 88 or AK on Txx or Qxx then yes this situation is more profitable.
However since we are assuming that he flats AK to a 3-bet then on Kxx and Axx we commit to play for stacks, which may not always be good for us.
Furthermore if he flats QQ+ with the intention of CRing his overpairs that takes the edge off our 3-bet plan.
If he does open with dominated hands to begin with I dont expect him to fold any of them to a 3-bet that often.
This will vary from player to player. I think it's quite optimistic to be in really good shape against his continue range
Now of course you can argue the benefits of retaining the two very loose fish in the blinds vs the diminished value of AK in a multiway pot - but clearly we have to account for the 18/12 regular on the btn who will continue with a wider range now and of those times we will be in a poor relative position.
If there was anything to swing the times it's close then this is it. Assuming the reg is good letting him in is bad, if he plays fit/fold then bring on the dead money.
Ideally I'd like to have more reads on the guy, loose passives are really easy to play postflop so don't assume that if you flat and miss the gig is up. His checking range is probably going to be super weak so he hands you the pot, if he cbets too much you can maybe apply some pressure (though thats marginal given his range).