Ordway is an okay artist but nothing special so is easily replaceable by the Marvel or DC.
Trimpe wasn't very good from about the late 70s on and it is surprising to me he lasted as long as he did. His best work was his early work on the Hulk.
Age doesn't really matter if you are really good or have something unique to offer.
If you are good enough, you are either old enough or young enough depending on your age, of course.