In that case, having them at full Chapter strength would make them larger than a standard RG/Successor; they are always understrength due to the genetic issues.
The Marines from the Raptors project were mini-Primarchs, whos ultimate fate is currently unknown I believe (not sure, I'm not up to date in the series), so a future book could have them all killed off, destroying the premise of your Chapter.
Of course you can imply it, such as saying the recruits take to the Gene-Seed very quickly, and are all brilliant quality Marines, but this will be branded as Mary Sue-ish. Got to be careful.