It depends how equivalent the players are.
If you have a fantastic 2nd string tighthead, but the other two are average, you may use the players in a more strategic way.
Exeter have 2+ very high quality front rows, and 2 pretty good backups. No other club has anything like this strength in depth.
I wonder if doing the same for the second row instead may be more productive. Their work in the tight, lineouts, defensive mauls, etc are such that they have to be extreme athletes to last 80+ minutes.