As far as I know, Ukraine has at least 1 fighter jet remaining.
Look up "Highway of Death" or "Slaughter Alley" from the First Gulf War.
The only logical conclusion to a 40-mile military convoy to be literally crawling through enemy territory, is to give the enemy plenty of time to prepare for it.
It's no secret the west is sending thousands of anti-tank missiles. Or that the Ukrainian forces have been very successful with what they had.
So, the only conclusion I can reach is that Putin is purposefully sacrificing that column.
Perhaps it is commanded by officers he wants to get rid of.
Perhaps he will use it as an excuse to escalate to "theater nukes".
Thought I would add that that tank thing could be a sign that Russian supply lines are failing and that would mean defeat for Putin. So I think he would risk trying to get a convoy through no matter the cost. As far as theater nukes go - that's his thing and he has been playing that thing for many years. There is a lot of Countries in the World that have nukes and most of them are willing to fight for democracy. Putin knows that so his theater nukes thing is over. Cold War is over baby and it ended in the Ukraine. Cheers!