Golol wrote:and even if the enemy has -100 power he will need about 1min to rebuild thw hydro so not really worth it
I have to disagree with this, at least partly. There does come a point where you have enough power that losing the hydro doesn't matter, but on some maps that moment can come quite late (TAG Craftious Maximus comes immediately to mind as a power-stalling map, but this applies to many others to a greater or lesser extent).
In any game where losing the hydro will affect the energy income (i.e. when the player is floating less than 100 energy), taking out the hydro is a very powerful tactic. You are forcing an action from your opponent, and hence putting him on the defensive to an extent - if he doesn't stop what he's doing immediately and attend to the hydro, he will lose sufficient build power that you can probably steamroll him soon enough. If he does stop and attend to the hydro, then you've gained a big advantage in terms of concentration on his part. He may also have to stop some or all of his production to get the hydro finished ASAP, plus if there is travel time involved his only option may be to make pgens instead, thus delaying him further.