I'm wondering how the military strategy change once Germany had been pushed back into their own country. I'm guessing that the West (Britain, France & the US) must have known the dangers of allowing the Soviets to gain all of Berlin for themselves and that the Soviets felt the same about the West.
And not to tack on a what if but could the Soviet occupation of Germany have been avoided if the German counter attack at Ardennes had not been successful and the West taken all of Germany before the Soviets even got through Poland?
Sorry for the clunky language its early.
Eisenhower didn't consider Berlin a militarily important objective. He knew it would be costly to take Berlin just to score some political points. The final division of Germany had already been decided at Yalta, regardless of who got to Berlin first. While some German units were anxious to surrender to the Western Allies, notably the Twelfth (under Wenck) and Ninth (under Busse) Armies, there were still plenty of die-hard SS and other troops that would make Berlin a bloody fight.
In addition, Eisenhower was getting information from his intelligence team that the Germans were preparing a 'National Redoubt' in southern Germany. SHAEF G-2 was convinced that large numbers of troops, including several SS divisions, were moving to set up a last stand in the hills and mountains around Berchtesgaden. Their assessment on March 11th read:
The main trend of German defense policy does seem directed primarily to the safeguarding of the Alpine zone. This area is, by the very nature of the terrain, practically impenetrable.
Thus Eisenhower was looking at a costly assault in mountainous terrain if the Germans were allowed to consolidate in that area. Logistically, he didn't want to try to support two major offensives simultaneously. So, rather than drive for Berlin, the US main effort was put behind Bradley's forces to take southern Germany before German preparations could be completed, and Twelfth Army Group was halted along the Elbe. But SHAEF G-2 had been wrong: There never was any National Redoubt.
See Stephen Ambrose, Eisenhower and Berlin, 1945