DPR matters in some computer games but in D&D, it is irrelevant. Removing a treath from the field is far more important than an hypothetical maximamuzed damage done. In D&D, being g at 50 or 1 Hp does not matter. You will stay at peak combat efficiency and so are your opponents.
Ho that orc must be at 2 or 3 hp, I'd better hit the ogre since it will maximize my DPR is simply an aberration in D&D. Kill the orc first, it might get lucky and down you in one fell swing.
No one will ever convince me that managing your DPR is better than removing threath. Ever....