Unfortunately the Diamondbacks have very few lefties. Corbin Carroll, Alek Thomas and Pavin Smith are the only left handed batters on their roster and Carrol is the only one guaranteed to be in the lineup. The Phillies bullpen is maybe too left handed heavy for this round, though it does seem like they trust both Strahm and Alvarado (and Ranger) to get right handers too.
The only spot for Soto is with one or two outs and a lefty up. But you don't want Soto facing Marte as he appears to hit lefties better than righties (and hes killing us). That reaslistically means you can't send Soto out to face Perdomo who doesn't appear to have obvious splits, because if you dont get Perdomo/Carroll out then Marte is next.
You could send him out vs Thomas because then you have Longoria and Perdomo and that seems a reasonable part of the lineup to navigate, though they could counter with Emmanuel Rivera.
I'm probably reading too much into left/right splits. I'm sure pitch type is far more important but I don't know how to look that up easily (and you are dealing with smaller samples). Something to figure out over the winter.