If Sentinels win Berlin and Champions would they complete the grand slam?
The only tournament they didn't win was Stage 1 Challengers, but the format was super weird due to the whole qualification to Master 1 thing.
If they win only champions I feel like calling it a grand slam would be weird. But if they win berlin and champions, hands down yes... Thats literally all international copetition won and qualified to them as #1 seed