E2=22pg/ml seems to be optimal for guys on TRT; in terms of fat loss and libido. I have not seen anyone offer anything deeper that that. E2 in the 30's is associated with problems.
If T levels are low, E2=22 will lead to some estrogen dominance and problems. So, yes, there is a need relative to T levels. That would be FT or bio-T as T+SHBG is not bio-available. [That distinction only has significance when SHBG are abnormally high.]
Higher E2 leads to more SHBG and less FT. E2 also interferes with FT at T receptors. So there can be compound effects, both negative or positive. The sum is greater than the parts.
So should E2 be below the 20's when T levels are not upper range? No solid consensus on that. Some keep there levels there. However, E2 is essential for proper brain function. When E2 gets near single digits, libido can crash even with high T levels. And low E2 can create confusion and depression for some. Low E2 can also make one emotionally dry and more analytical, but taken to extreme one does not want to be emotionless.
Doc is right to some degree, but does he thing that E2 should be very low? That would be wrong.