F-16s are well and truly what is required for Ukraine in the defense of their nation in the current war.
The Ukraine air force speak here on why:
https://kyivindependent.com/air-force-incraeased-russian/
More here:
https://www.pravda.com.ua/eng/news/2023/04/8/7397035/
F-16s will allow the war to be stopped sooner.
They appear to be clearly what is needed at this point.
Ukraine have shown the ability at this point to learn quickly too.
In terms of training being minimal needed for them.