My daughter works with she nearly 19 Now  been with since couple years  she does  back I do fronts, she can easily use the 35 extreme when needed her standard pole is 18 extreme or the 25 extreme 
we work well together streamlined how we work now, one pole each with a spare 25 extreme I do have the extra three sections to take 18 pole to 35 if we need slightly longer just slide on for that job when needed 
For efficiency and speed of working, we use the electric reels saves energy, " neither of us have any delusions of needing to man up' I'm getting older she's about 5:4 and 8 stone at a push 
We use extremes set up with tubeless kit from exceed and uni valves And only  I use only pole hose from exceed on reels been on now about a year I feel it's quicker no winding up of pole hoses also less water run of in van quicker winding in and less annoying of winding pole hose up 
We clean quite fast now I think , average 5 1960s houses and hour if there close enough, we often use sill cloths as sometimes in year we find it easier on downstairs whilst one is winding in, there's  no invoices left it's all texts Or emailed invoices or go cardless 
Prices are very high In the south, so it's easy together to make a good wage  she works two And I work 4  days 
I feel getting the pressure right For your style of cleaning is important also one pump one controller one hose reel per person, if someone works with you they need to do upstairs to optimise speed other wise a lot swapping and walking around the house 
We use minimum water 500 litres a day as we're fairly efficient now 
Hope you manage to find good Improvemnts that work for you this is what works  for me