Friction Loss Calculator Swimming Pool Has 2" Pipe From 2 Skimmers & 1 Drain. Does That Give Same Friction Loss As One 3.5" Pipe?

Swimming pool has 2" pipe from 2 skimmers & 1 drain. Does that give same friction loss as one 3.5" pipe? - friction loss calculator

I need the total dynamic head (TDH) for my pool before sizing the pump to be calculated, but information on the Internet for the loss of friction and TDH appears to assume that only a pipe in the loop between the pool pump and back to pool. I have 3 tubes in parallel 2 skimmers and main drain. Also 2 pipes again in parallel. How can I include in the tubes in parallel? Two tubes have the same region as a 2.8 "pipes, tubes, three have the same area as a 3.5" pipe. Should I pipe sizes equal, or what? Thank you in advance.