Difference between new and old Space Marines?

I've built my Tactical Squads with heavy weapons but after testing I don't really want them, so those models are going to be transferred to an eventual Devastator Squad - however, I need some guys to replace them. I have some old unbuilt Tacticals lying around and I wanted to ask; would it look out of place for there to be one old Tactical amongst the new ones? I don't think they changed that much but I don't have any of the old models built to do a comparison.

Thanks!