Of course they can.
500+ militia - MILITIA - held off 6-9+ thousand of Ukrainian forces for nearly two weeks causing huge causalities and kills upon the Ukrainians before withdrawing.
Sez you. I don't buy those numbers for a second.
But let's say they did hold out for some period of time - that doesn't address my point. First, these are "militia" who have years of experience fighting - not a bunch of fat conscripts or short-term reservists years or decades removed from any military experience...if they even had any at all.
Second, they were tasked with digging in and defending a specific point in a built-up area with a continuous line defense - not tasked with covering large streches of open territory that would be the case in Kherson or Zaporizhzhia oblasts, which is where I said they'd have the greatest problem.