The shuffling problem was much worse in 1.0.0. It has been gradually getting better
Agreed.
and has certainly gotten better instead of worse in 1.3.3.
I'm not certain about that. With AI Germany now garrisoning conquered provinces, it has added another AI branch of theater/army/division realignments to current force disposition. As evidenced here, where AI Germany while at war with Russia reduces the Eastern Front army down to 8 divisions, while increasing the Europe Theater Garrison army to 209 divisions. In 1.3.2 it is unlikely it would've done that because AI Germany didn't really do garrisons.
Germany simply does not manage to produce enough units by the Spring of '41 to accomplish its required tasks. It is short handed. That means that shuffling is more likely to be called for.
To add on to that, it also doesn't manage its theater/army make up very well either. Like using MARM's for garrison duty, and not producing cavalry or divisions specific for garrison duty, or as evidenced above reducing an active combat front beyond any sensible proportion, or putting 60 divisions in a single province, or shifting 5/6ths of a 200+ division front to the poorest infrastructure areas on the front, etc....