For someone who's tired, you do go on. Once more tonight.
I don’t know why you keep claiming to have total objective and unassailable knowledge of the motivations of fictional characters. That isn’t how fiction works.
Yeah, I know. That's why I didn't.
Characters like Rosalind and Viola aren’t real people, they’re made out of words. So there isn’t any final truth about why they ‘really’ dressed as boys. There are interpretations, and I don’t think it would be difficult to build a trans one if you wanted to.
Rosalind: "Were it not better, / Because that I am more than common tall, / That I did suit me all points like a man? / A gallant curtal-ax upon my thigh, / A boar-spear in my hand—and in my heart / Lie there what hidden woman’s fear there will— / We’ll have a swashing and a martial outside, / As many other mannish cowards have / That do outface it with their semblances."
Viola:
"For such disguise as haply shall become
The form of my intent. I'll serve this duke:
Thou shalt present me as an eunuch to him:
It may be worth thy pains; for I can sing
And speak to him in many sorts of music
That will allow me very worth his service.
What else may hap to time I will commit;
Only shape thou thy silence to my wit."
Of course Emperor Hadrian wouldn’t have said he was proud to be gay, as the word gay didn’t have that meaning then, but that doesn’t mean the concept of pride (as opposed to shame) in same-sex attraction in the face of social condemnation didn’t exist before 1970 and the first pride parade. I’m not an expert on Ancient Rome so I can’t tell you about that period specifically, but there are certainly examples of expressions of what we would now call gay pride in pre-20th century materials.
It was massively shaming to be the receptive partner in the ancient world. Young men were allowed a period of being 'initiated' by older men, but much scorned if they continued. See the rumours around Caesar and Augustus.
Similarly, yes of course someone in the Renaissance wouldn’t have said ‘I identify as a woman’ because that wasn’t the phrasing then, but that’s not the same as saying that no-one in a male body ever saw themselves as a woman prior to about 2015, or whenever you want to set the arbitrary invented boundary.
Perhaps, perhaps not. But they weren't, however they saw themselves. And the culture at the time certainly wouldn't have encouraged them in the delusion.