I like the perk. I believe its at the end of one of the Malevolent aggression lines isn't it?  Its does seem a bit OP, however it is a top tier perk that you worked for. On the flip side you still have to pay maintenance on all those ships..how much money are you earning after a few turns?

Yep you are correct. Still you are paying all that maint on those ships. 

This perk is on the pragmatic track.  I just did it.   Had to compensate on my tax collection as my economy went south!   Also had to spend a lot of time organizing and fleeting up the new ships.   Garrison duty I think is indicated, as they have poor speed.   Hmmm, I am not sure these ships are much more than cannon fodder.  The three ships were beam, missile, and mass driver with corresponding defense.   At the current state of my game the last two won't be worth much in an actual battle,and the first one doesn't have enough hit points to last long.

However, the drastic improvement in my Power score means my diplomatic situation improves a lot.   On about turn 200 I have only met the Altarians and the Drengins, and I am kicking the Drengins pretty hard now, while the Altarians are close friends.   But some of the unknown AI are surely going to have sizeable fleets.   The diplomatic cost of "You have a weaker fleet" is a very bad thing.  I think it is what caused the Drengin to go to war in the first place.   Of course, they aren't enjoying it.

Course, I imagine the AI can do this also...

On an Immense map I had 82 colonies when I got the 3 ships per planet from the practical ideology bennie. Jumped my power rating way above the others and the maintenance was very large. Luckily I had enough income to cover it, but this unexpected cost will shock some players the first time they get it. So this is an "expensive" benefit, literally.