I would be more likely to simply have reserves just not give shredders, since they're pretty unique in the whole "getting a handful of them is almost as good as getting the bonus ship type itself" thing.
NOOOOOO!!!!!

Is that based on a rational objection, or an emotional one? 
I guess the big question there is: if you know how to "grow" a swarm from a bunch of reserves (or parasited shredders, would need to make them immune to reclamation too), do you therefore think it's not a good idea (due to redundancy) to pick shredders for your starting bonus type? I mean, sure, it's easier to build a swarm if you can build the first cap at your docks, but the "marginal utility" of having the bonus type is just way less if you already have the ability to raise a swarm.
For that matter, if you get Shredders from an ARS, do you feel like you didn't get a good value because you could have raised your own swarm from a reserve?
A mix of both I suppose.

I got lucky and had a mkIII z reserve one jump away from my homeworld and it contained 8 viral shredders with assorted other ships.
I now have the cap of 1500 to keep a watch over the direct line to my homeworld but it takes a ton of energy to keep them alive. Matter of fact had several brown outs as the growth rate far exceeded my early economies ability to keep up with them.
Now if you want to reign them in a bit I can understand but please don't take them away as getting them in a optimal place on game start as the first bonus ship or landing a lucky dice roll on an ars is fairly rare and they are simply awesome as a choke defence or quick killer of a growing blob of ai ships at a choke if you send them through.
Plus getting to a z reserve that isn't in a place that is easily reached can be a chore in itself.
Dunno just seems to me they are pretty well balanced atm but then again I suppose I am more of a casual ai wars player so I can't speak for the hardcore amoungst us.