There was a report this morning that the Ukrainians engaged Chechnyan/sp fighters in the east and the Chechnyans either folded or did not prevail. It may just be one engagement but when one becomes two and if the same thing happens with the big, bad syrian foreign fighters then that is a bad sign for Vlad's attempts to fight his evil war with mercenaries. He is counting on them a bit too much.
Yes, the Ukrainians are experienced fighters now, but in addition they are being advised and supported by the Americans. The American military is excellent - smart and capable and adaptive when left to themselves. When the Beltway politicians and generals get involved they become a complete clown show, so that is equally true. The american military is designed to work in units that are flexible and use their own brains and skills to adapt. Just what the Ukrainians need. This is in contrast with the Russians whose military is still a top down command and control structure. They put a massive force together and point it at the enemy and send them out to hammer away. It works when it works. The minute they need to adapt to some changed situation though, they dont know why they were there in the first place nor do they know how to collaborate and put together a unit by unit strategy.
Not saying the Americans are on the ground there . Not saying they are not either.Their influence and support are though.
I have very little doubt the CIA is on the ground and so are contractors. Not fighting but on the ground intelligence and support, no doubt in my mind. The Russian-Ukraine war will be hay days stories in the halls of Langley for decades.