Wagner based on the personnel and formation of the offense.
Since the Defense won't know the formation to substitute in, go by the personnel.. so in this case, Wagner would fit better.
If it's 11 personnel and Rams wanted 1 LB, then Jones.
Especially if WRs are in a bunch on the wide side.
Jones can get to the outside quicker, especially if it is a WR screen.
Wagner based on last year's tapes struggled to get outside on WR screens.
It's going to be milliseconds difference as Wagner will react faster than Jones, but Jones will cover ground faster.
On the outside, Jones is more of an aggressive tackler while Wagner is more hesitating now.
On the inside, totally different, Wagner is still really good reading the gaps and getting off blocks. He was solo tackling Henry without giving up much yards after tackle.. which is just super impressive vs someone like Henry. Reeder/Rapp would have given up 5 yards after initial contact.