Complex sentence: It was given low priority in manpower, anti-aircraft and anti-tank weapons and air support and consisted of five divisions, two were over-age reservist "Serie B" divisions and one was a West African unit from Senegal.
Split into simpler sentences: It was given low priority in manpower, anti-aircraft and anti-tank weapons and air support, and consisted of just five divisions. Two of these were over-age reservist units, or "Serie B" divisions, and one was a West African unit from Senegal.