Complex sentence: With Axis aircraft based along the length of the route to Malta, air power had decided the course of events, although the diversion of Axis bombers against the convoys had been of some benefit to the British as they conducted the "scuttle" to El Alamein.
Split into simpler sentences: With Axis aircraft based along the length of the route to Malta, air power had decided the course of events. On land, the diversion of Axis bombers against the convoys had been of some benefit to the British as they conducted the "scuttle" to El Alamein.