You are completely mischaracterising my argument.
Pro-trans people do not, to my knowledge, cheerlead for oppressive regimes.
No, it's just not a very good argument.
What you are essentially saying is that the problem isn't with having some common cause with an objectionable group or ideology. Rather it's acknowledging that this common cause exists. So it's absolutely fine that TRA types and the Islamic Republic are pushing similar views on a particular issue, provided everyone pretends it isn't happening and certainly as long as nobody stops to think about why a homophobic, misogynistic regime might find this ideology attractive.
This quest for ideological purity isn't going to help us, and it particularly isn't going to help when so much of the progressive left have entirely abdicated any responsibility or common sense on the issue. If you were simply saying that we should point out when someone's being an arsehole regardless of whether they correctly identify the threat posed by trans ideology to women, that would be a reasonable point, but you've gone rather beyond that. When so much institutional capture has gone on already, lots of luxuries are not open to us.