If you aren't pinched/kinked, there should be no appreciable loss of flow. Flow rate will affect high RPM/high speed operation, not low speed. The CONDITION of the hoses is important though. If they're hard, cracked, or look "wet" then they're done. When routing replacement hose make sure you route it in such a way that the hoses aren't rubbing on anything. If that means shortening or lengthening any hoses when you redo it, use your best judgement.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]