I'm not so sure Hagar is locked in as the starter. Doesn't Howard play ILB too - I know he's recovering from injury. Theres also no mention of Dakota Allen. Patrick can also play inside - I think that was his natural position. It's possible they go with a younger player and then add Kiser back when he returns from injury. Hagar does contribute on special teams so maybe that's how he sticks.
The Rams are NOT keeping 3 QB's - not to sacrifice a player at WR, DB, or LB. Neither of the 2 guys down the depth chart seem like keeping anyway. Maybe practice squad.