So, the challenge is: make a scenario, with post-1945 PODs, where D-Day and Operation Barbarossa weren't the largest amphibious and land military invasions in history anymore, respectively. That means you have to make two invasions which can beat:
D-Day:
175,000 troops
~5,000 ships and landing crafts
11,000 aircraft
Operation Barbarossa:
~3.9 million troops (including reserve)
3,600 tanks
4,389 aircraft
46,000 artillery pieces
Multiple bonus points if both of your hypothetical invasions are happened on a same timeline.
D-Day:
175,000 troops
~5,000 ships and landing crafts
11,000 aircraft
Operation Barbarossa:
~3.9 million troops (including reserve)
3,600 tanks
4,389 aircraft
46,000 artillery pieces
Multiple bonus points if both of your hypothetical invasions are happened on a same timeline.