Armor without air support wont do the job. The new tanks on line this summer need much more air support. Plus Ukraine has lost some of their best soldiers so far and the untested reserves will be going against entrenched Russian forces with massive fire power.
And the massing of Ukr forces will be very visible to the Russians so they will have plenty of time to counter it.
Ukraine shows determination to “stay the course” since their declaration of independence.
Just as the USA did!