xhoel, Rumanian pools are not in such a great shape, usually they have a shortage of men and not that much armaments.
Denniss, in the latest data I see ZB53 is configured to import from German MG34 at 1% rate. I don't think this is necessary. I think this was a separate Czechoslovak weapon, not exported MG34.
Also, initial build may be increased a bit, to kickstart the process of upgrades (150 is needed to switch one division).
Finally (and this may be main source of slow upgrades), the previous MG is marked as upgrading to ZB53, but has end date 9/45. So it is never obsolete, but it should.
chaos45, not messed, but vastly improved. The new system is much better at utilising pools, available resources and maximizing combat power gained from these. Sometimes data configuration may inhibit the code to operate with desired efficiency.