The union puts out a "daily departures" chart once a month, Looking at the average daily departures for July, PHL has in the mid 20's, EWR has just under 110. That alone tells you there's a lot more options for departure times and types of trips.

I took a look at the PHL schedule and was surprised to find very few single day trips. (prefer a lot of single and 2 days) There's quite a few single day trips at EWR.

There's 150(ish) FO's at EWR and 75 (ish) at PHL, doing that math, the more desirable trips are going to go a lot faster at PHL, or put another way, you're going to have to be farther up the food chain to get what you want.
I don't know of a breakdown I can get to showing how many 2, 3, 4, or 5 day trips at each base, I just went through the union's market planning podcast and there's nothing in there that lists that.