I am using a calculator that Deere provides to dealers. It does not specify how much hydraulic demand is attributed to each feature, I just enter them and it gives me a total. It is usually pretty accurate, maybe runs a couple gallons high in some cases. You can probably get by with your setup just fine for a year. I don't mean to scare you, I just think you would be doing yourself a favor to have a backup plan in place in the event it doesn't work as well as you thought.