If I understand what bair was saying in relation to TAG vs. LAG preflop - I think you're basically talking the tight vs. loose portion of that. Obviously both bet certain hands preflop...TAG players just play and bet fewer.

Post-flop, both players will be aggressive when they at least have some sort of decent draw. This isn't the same as bluffing, though it can evolve into bluffing by the river if the aggressive player has hit nothing, but reads that the other player has nothing worth worth raising or there are enough scare cards, and so the aggressive player continues to be aggressive - and sometimes bluff his opponent out of the pot, sometimes not depending on the player and the holdings.
But - both aggressive types will also fold if they don't have the proper outs/odds/+EV and read the opponent clearly has them beat.

Now, why in the circle does LAG beat TAG given those definitions?
I don't see a clear answer to that - unless my assumed definitions are incorrect.