Complex sentence: From 1941 they received instead one artillery regiment (2 battalions, each from 3 four-gun batteries) with 24 howitzers, but in early 1942 only one battalion (2 batteries, 8 howitzers) remained.
Split into simpler sentences: From 1941 they received instead one artillery regiment (2 battalions, each from 3 four-gun batteries) with 24 howitzers. From early 1942 only one battalion (2 batteries, 8 howitzers) remained.