Out of the remaining 4, the one with the least innings is Brice at 8.
If we didn't have him from Day 1, those innings would likely have gone to DHern, Taylor and Valdez, all at 11.1.
Yes, they could have absorbed those innings.
But for whatever reason, they wanted to have a look at Brice and the other 3 as well.
They knew why they wanted 14 pitchers, and that's all that matters.