Complex sentence: His tactic was somewhat successful: it enabled about 1.8 million German soldiers to avoid capture by the Soviets, but it came at a high cost in bloodshed, as troops continued to fight until 8 May.
Split into simpler sentences: His tactic was somewhat successful: it enabled about 1.8 million German soldiers to avoid capture by the Soviets. However, it came at a high cost in bloodshed, as troops continued to fight until 8 May.