The worse choice for the Ukrainians was to not hit the Russian military inside Ukraine.
The courage of these Ukrainians who fight for independence impresses me to no end.
It may not have anything to do with the outcome, either way.
Russia's calculus is purely political at this point.
They are not worried about an insurgency in Easter Ukraine should the decide to annex it since a LARGE portion of the population is ethnically Russian...and another significant portion is sympathetic.
It's not like the USA is going to build a sea-bridge to Odessa and drive 1500 Abrams tanks to Donetsk. Nor are we going to project any other form of sufficient power to challenge the Russian Military openly in the field.
The is NO VIABLE military counter to Russia in Ukraine.