My workflow looks like this, I modified the data a bit, but:
First call is done with 1000 elements (takes around 15 secondes), the second one with 663 (takes around 7 seconds, but in the merge, it is the opposite (but the call with 1000 elements takes more time)
(I can’t upload my workflow with data because it is too big. and I can’t upload json or txt files..).