Me thinks that using 'outside' blood will always strengthen the offspring. I do have pens with individual breeds, but I have two larger pens where I have one roo and his lady/ies. I find the babes from the crosses are stronger, more robust and over all just better kids.
Honestly I'm just incredibly picky about who gets the birds I'm raising too! I have 7 pens, only two pens have different breeds (roos are not the same breed as the hens), however they produce more robust babes that my purbreds. Wink.That would depend on what you have, honestly. I'm incredibly picky about breeds and I keep them all seperate so I don't get mix ups apart from my mix flock
