Think this is more a case of limited data as the 469 innings in OF total has Happ at 2.2 UZR/150. Almora in the OF in general has 811.1 innings with a 10.3 UZR/150. Defensive data in general is very hard to determine on short sample sizes. For example, Almora in 811.1 innings has only 172 data points. Happ in CF has 58 in 317.1 innings. It's also worth noting that Almora plays so sporadically that I imagine it's harder for him to get in a rhythm.
Long story short it's pretty obvious just watching them play Almora is a better defender. Whether or not Happ's bat is worth more with his more average-ish defense is an interesting debate worth having but just citing uzr/150 on short sample size doesn't really mean much. I think given the lack of offense of late you're fine going with Happ. Frankly think it's more a case do you want Almora Zobrist or Schwarber in the line up and you just move Happ to whomever you want to sit in LF 2B or CF.
CF:
Innings Happ: 317, Almora: 574, Jay: 289
There is enough data there to make a legit judgement.
ErrR: He is at -.7 But leads the CF in UZR: 2.8 and RngR: 2.9.
So over all saying that he is a avg to below avg CF is really unjust. That is saying Schwarber sucks in LF when his numbers are at: RngR: -.5 ErrR: -.9 UZR 3.2
Now Almora has had the most innings at CF. The sporadic playing time IMO would affect his timing hitting vs his OF play. But he has excelled in a part time role. the splits don't lie.
Now I'm online with Happ in CF and Almora starting vs LHP and Happ moved over to LF those days. But we should not be seeing Jay in CF starting IMO.