Tons of good ideas here, thanks for all that!
Here's what's in so far:
* Zenith viral Shredders are now immune to reclamation, as they unintentionally could multiply from 1 captured by a player to hundreds or thousands.
** Thanks to Ozymandiaz for reporting.
* The parasite line of ships has had their stats rebalanced in general, and linearized. They now have a lower attack speed, but massively higher attack values (which they now need).
** Thanks to lovekawakawaii for suggesting.
* Leech Starships now cost 2x as much energy to run, and their stats have been linearized also. They also now have 10x fewer shots, and do 10x more damage than before.
** Thanks to lovekawakawaii for suggesting.
* All mark V ships are now immune to reclamation (this was always the intent, but a few slipped through before).
** Thanks to Toll for reporting some of the lapses.
* Ships with the reclamation ability are now only able to reclaim ships that are, at most, one mark level above their current level. So mark I ships can reclaim mark II ships, and so on.
** Thanks to Wingflier for suggesting.
* When reclamators damage an enemy ship, it will only be reclaimed if at least 50% of the damage to that ship was done by the parasites of the current player.
** Thanks to superking for suggesting.
What else I'm considering if this isn't enough:
Making it so that reclamation can only happen if your ship cap for the specific ship type is less than 20% of the total ship cap for that type. Thus, as people pointed out, you can then only do so much with reclamators, you still need the higher-mark ships to be directly built, etc.
I've started with the above only, though, to make sure it's not too overboard. I was sorely tempted to do the last bit along with the rest, though. Parasites were SO far out of balance it's not even funny, because they could circumvent such an enormous part of the economy as well as the need for Advanced Factories, etc.
Getting some free ships, including some ship types you otherwise wouldn't have, is cool Circumventing large parts of the economy, and advanced factories entirely, is not cool.
Let me know how it seems in the next version!