If you think you're hiring them...
Oh you sweet sweet summer child. I assure you, they're there to rape, loot and pillage. The last thing on their mind is fighting a conventional military.
It's a degenerate's last resort to allow them on one's own land knowing full well Russians will still treat YOUR people better. If Ukraine does allow them, then it truly deserves to be conquered by the Russians and have it's dignity reinstated because yes, it's a mere barter of nationalism induced feeling of inadequacy of pride for your culture, your people and all the other nice things you think you stand against the Russians for.
Also, I'd reckon the public backlash would give more recruits to the LPR and DPR which will have a long term effect on Ukraine's influence in the region. You might repel the Russians right now but if there's one thing that's true about the Russians, it's that they're tenacious and will be back.
The Syrians though?
Hahaha
Turkey's surviving on borrowed time (and plundered riches) and soon will have an economic crisis which will slap it back to the reality. As I've always said, the last Khalifa was Mia Khalifa and there'll be none after her. Definitely not Erdogan ffs.
Suit yourself though, it's your country.
Till it isn't.
TLDR- I consider Ukraine to be a self respecting nation for standing up to a relative giant like Russia and do not think they'll go for that strategy but if they do, count me as a Russian shill till Ukraine loses.