Problem with HRE is that its troops are far inferior to the low-cost ones from Venice and Milan, it happened in all my modded games to see the HRE become vassal of Milan with the latter become the middle-europe superpower.

Things start to change towards 1200 (with 2 turn/year) probably because of some new kind of troops from HRE filling the gap.

Still these considerations are just raw experimenting without being able to have a units comparing spreadsheet.