I think you have missed a trick here - if you conscript everyone then you can sort things out in basic training. There are plenty of jobs in the military for which being 'fast and strong' is no longer a necessity. Modern militaries are not the same as the medieval battlefield or the Napoleonic era.

So if you conscript everyone, you can then begin a filtering process. It may not make much sense to put young women in the running around with guns and shooting jobs, but there are enough snipers and fighter pilots (particularly in Russian WWII history) to suggest women are very capable of performing battlefield functions. Here in the UK, the vast majority of 'war work' done during WWII was done by women, particularly in code-breaking, reconnaissance, intelligence gathering - they weren't conscripted per se but may as well have been. If Putin had gone North into Norway or Sweden, he would've been opposed by an army made up of the entire working-population rather than half. Neither Scandi country differentiates between sexes when it comes to conscription.

And my critique here isn't of what Ukraine did. Decisions were made quickly and with backs against the wall. My critique is a failure to talk about this as a feminist issue.... or even raise it as such. As other commenters have said, when they've raised a question about it with feminists the response is usually 'it's nice to see discrimination happening the other way round and men getting the worse end of the deal'. That's an okay position to hold, but it isn't a feminist one - and it suggests, to my mind at least, there's a core of misandrist thinking at the core of what we'd term fourth wave feminism.