Yeah... the opposite is definitely true.
HRT has hit me HARD in terms of losing strength. I was never that strong to start with, at least not for someone of my size, but what strength I did have has pretty much been sapped.
Back in May, I was playing volleyball. Before HRT, my biggest problem while I was serving overhand was always trying to keep myself from hitting the ball over the back line, because I hit it with too much power but not enough topspin. But this time, when I tried to serve overhand, no matter how hard I hit the ball, it never made it further than halfway into the opposite court. I lacked the physical ability to hit it out of bounds. And it was kind of weird, because a lot of times where I felt like I was hitting the ball perfectly based on muscle memory, suddenly it was falling short of the net. I actually had to abandon serving overhand because I was hitting it too short half the time. And that was 5 months ago. I've been feeling weaker and weaker with every single month since then, and the last month has been the absolute worst in terms of simple little muscle-exertion activities causing me pain.
Yeah... it happens. Testosterone is definitely the muscle-building hormone. There's a reason why steroids exist. And we're basically taking reverse-steroids.
But the theme of transness is that to us, that hormone feels wrong. What's right for us is exactly what's wrong for FTMs. Yes, I had more strength with T still in my system. But it also made me feel tense, cranky, constantly on edge, lacking any emotions except annoyance and irrational anger, plus the sex-drive always felt wrong, and I hated how it felt like it was controlling me. Whereas once E was in my system, I immediately felt calmer, more relaxed, peaceful, in control, as if every part of my body was taking a deep breath and saying "Ahhhhhhh...." ^_^
It's just because our bodies are designed to run on the opposite hormones. And once those hormones are finally in us, finally everything starts feeling "right." That is universal.