Villain's range is all that matters in this hand.
A standard TAG calls a 3bet OOP with..?
In my experience: Medium pairs. Maybe AQs. This is very, very rarely (basically never) AK when we're dealing with a reg at these levels, because he'd have jumped at the chance to backraise it. AA is a lot more likely than AK. It's not going to be KK much either, since again he'd most likely backraise it rather than see a flop and risk killing his action. QQ goes the same way.
So we're left with 77-JJ, AA, AQ, and maybe KQs. Sometimes KK, depending on our own image. Unless standard TAGs at Stars play differently than standard TAGs at Party.
I bet this flop with AA and better, and check back almost every other made hand. As soon as we bet, we're committing, and I don't see any particular reason to commit versus a range that is going to have us crushed when they come along for the ride. I'm of course also betting air and strong draws, but again, they're hands that I know what to do with when raised.
If this were me - and I'm sort of a standard tag, I guess - my range preflop looks like what I described above. If I think Zach marries the pot once he 3-bets, or that he folds all the time postflop, I might continue with smaller pocket pairs too, playing for set value and fold equity postflop.
There's no point for Zach to bet versus me on this flop, because I'm not putting in anymore money unless I bluff or have him beaten. There are only two draws in my range and that's KQs and AQs, both of which I'm probably getting it in on this flop with, and Zach has poor equity even against those. And I never pull a pure bluff on a flop this wet.
So if we bet, what hands in our opponent's range are we hoping he folds? Or which ones are we hoping he calls with?
With AJ, the case for betting is a bit better since AQ has fewer outs, but if I'm still checkraising you all-in with AQ, that matters little since you can't really call a checkraise with top pair against my whole range.