Regarding the availability and sourcing of Leos, this blog post is worth reading. Finland has relatively big fleet of Leos in good condition, the issue being that being out of NATO they are needed as deterrence. However, if help is available in case of Russkies getting bad ideas, the Rheinmetall ones could on my opinion be ear marked to Finland and the Finnish 2A4's be sent to Ukraine. The Leos could be in Ukraine before winter is over.
https://corporalfrisk.com/2023/01/15/free-the-leopards/