Just a note re. artillery (nitpick, I know), should be:
1) not 149mm but less as a divider (Italian 15cm howitzers were in fact 149mm for example
)
2) Distinction by purpose as well - 105mm field guns were considered heavy assets usually and were distributed scarcely, if ever - IIRC, for example in German "official" TOE from early war, there should be a battery of 4 105mm guns attached to sFH (15cm) Bn of divisional artillery.