I started on E only, almost 5 months in with AAs. I had relatively low T to begin with, so wanted to see how my levels responded with just the initial dose of E. I was hoping to avoid taking too many things, to try to separate out what the effects of each was, and in part just because I just don't want to keep track of too much.
In my case, 4 month testing looked as good as it could, T wiped out, E right where my Endo wanted it. Everyone has wildly different hormone response though... but personally, I think starting on E only will be fine, then you can see where to go next after the 3 month blood tests and at that time, if you start on Spiro too, you'll better be able to sort out what effects it specifically has on you vs E.
-Kate