Scenario 1: Take frequent short positions for a day or two and pay less interest but fee/profit ratio is higher.

Scenario 2: Take 1 lengthy short position and pay more interest (as we're borrowing for a longer time) but fee/profit ratio is lower.

Let's assume that in both scenarios we make profitable trades.

So which approach has a higher EV?

I suppose you may answer that it depends on what the interest rate you're paying is vs. the fees your exchange charges, but beyond that if someone could shed some light on this that would be cool.