Terminator: Dark Fate introduces the Terminator rev-9, part regular Terminator, part shapeshifting alloy. Notably, it can separate said two parts, in order to have not one, but two deadly Terminators after its target.
However, in some of the fights (at least the last one), it splits, then merges itself back. I can understand the need to merge after the fight (go back into infiltration unnoticed), but why during a fight? Especially, it seems that both forms are combat-ready and independent.
Why not keep split in two, keeping the good guys in separate fights to increase the chances of getting to Daniella?
Out-of-universe, it might make for a harder fight to process (by filmmakers and viewers), but what about in-universe? Is it a technical limitation of the rev-9?