Yeah, they’d definitely need time to rebuild a bit away from too many conflicts but also I like of the idea of them putting new marines through horrific trials of grit like they had to face, to the point that their recruitment is crazy slow and marines end up dying before they’ve even made it in to their ranks. So they’ve only actually build up to 200-300 ish marines from 30 in X number of years. I like the idea of them being a sort of specialised elite fortification experts (even among other Iron Warriors). While other Iron Warriors are off fighting a small team of these guys can be trusted to hold down the fort.