Russia has a military of just over 1 million personnel, of which nearly 20% are now deployed to Ukraine where they are demonstrating their abundant failings across command, through equipment to grunts in the mud.
I don’t know if you know this or not, but Russia has rather long borders with multiple nations, all of which are guarded by this same poorly equipped, poorly commanded and corrupt military.
Of course Putin could start thinning out his already questionable border units to bolster his failures in Ukraine or he could start admitting to the Russian public that it’s going so badly that he needs to start conscripting and partially training more lambs for the slaughter.
So yes, you have a point, Putin could increase the numbers of ill trained, ill equipped, poorly commanded, sullen youths.
After all, he probably sees no need to feed and equip them.
if each does his duty to stop a Ukrainian bullet, eventually the Ukrainians will have no bullets left.