Should have used 1.5 inch hose.
I would disagree , he should have had the right motors ... and 2"
There is one powerful 7.2 but he wouldnt have had those as it would push ashbys over their 13amps . Chances are he had two 1300w 7.2s perhaps because the owner selected a 600psi ..or was just used to 7.2s on a previous machine .The 7.2 is also unlikely to have the extra bit of cfm o fthe electro that can make a difference in series.
If you want to improve a standard sd/hs enforcer ... a second hd motor is just 140 , there is little reason not to a least try it out . That said the sd/hs was almost as good standard . At 50ft 2" my wand at least is griping and sucking at the carpet in a way u dont really get with two vac parallel .
As for that ' series has poor airflow thing ' stil one finger into the 2" hose and you feel little airflow ... but put a few fingers in until the gap narrows and airflow goes crazy ... vacuum will create cfm under cleaning conditions .
All that said ... dont expect an enforcer to be like a truckmount ..
you need the booster for that