You'll get different opinions, and people all respond differently, so you'll have to see how you feel and get your test and E2 levels from bloodwork to really get dialed in.
For me personally, 200 mg/wk TestE split into two per weeks 3.5 days apart, plus 2x 250 IU HCG puts me at 1,250 to 1,300 ish test on the morning of the next shot.
That's a bit above the upper range of normal, which I guess I'd consider to be 1,100 test.
For me personally if I don't take any AI that puts my E2 in the 50's to 60's range which I think is too high, so therefore that dosage i required some AI. How much varies again, but I'd say 10 mg EOD would be more than enough - about 35 mg/wk.
You mentioned 50 mg/wk which I think is too high, and you also said every 3.5 days which is too long. exemestane has a short half life so every other day is the upper limit for for best effectiveness. That's kind of awkward EOD if your shot frequency is 2x per week. If you wanted to keep it same day as shot 2x per week think about switching to arimidex