With most things here, this is all down to my experience. Estrogen isn't the issue IMHO (For me, YMMV) - it's SHBG that really cuts down on the effectiveness of Testosterone, and by extension (and more importantly) DHT. Sure, some of us are high aromatizers, but a lot of that can be mitigated by good diet and body fat levels... There's not a lot you can do about high SHBG without medical intervention. And that's why I love Aromasin, in very low doses of around 3.5mg/e3d - it helps with both E2 and SHBG. Adex, Femara, and even some of the OTC Anti-aromatases are just too crushing for a moderate dose TRT (IMHO). Reducing prolactin can have as dramatic an effect as reducing Estrogen, depending on your reasons for going on TRT.
I'm a firm believer in keeping Test and Estrogen balanced / high. I feel better when both are on the higher end, but that's not to say there's no side effects. Any time you crush your E2, you're signing up for misery... But I don't believe it should go unchecked. Depending on what your TRT is for, prolactin control can be as important as an AI.
I suppose my takeaway is that a healthy approach to TRT is to have everything on hand, and self monitor as necessary to ensure a healthy prognosis. Every week can be different, and if you're doing it without direct medical supervision / consistent lab work, you should have all your bases covered.