A-10's are very much not F-4s, way more 'basic' hardware wise especially with all the modern upgrades. I mean F-4 was one of the first fly by wire aircraft which means a shit ton of wires and bulky computing systems. More software now days than hardware but software issues can be worked on remotely to a point. Training is going to be time consuming on either platform but what has been said is that A-10 is easier to fly and maintain but harder to master. Main thing here is this- Ukraine already has techs that work on older equipment like the SU-25, they have no one working on something close to a F-16D. Even their MIG-29s were the older non upgraded ones from their time in the USSR, only ones that got modernized were the ones that they use to train with.

Main issues are that Ukraine currently has zero airfields capable of fielding F-16s nor do they have the capabilities to defend such a base while it is being built. As well as F-16s that are ready to be sent are non existent. Sales of them as on back order for years to other countries and even the older airframes need updating/repairs. Sure they are sitting around in the desert but that does not mean they can fly combat missions. Even training aircraft are hard to come by since so many new pilots are being trained on the airframe by different nations. There are A-10s available to train on plus once again Ukraine has SU-25 pilots with no craft to fly that already have a basic understanding of how to operate it.

A-10 can take off from a road. Now Gripen can as well and that would be a fantastic choice but again- WHO THE FUCK IS GONNA SUPPLY THEM