I don't think England would drop Labuschagne if they had him. They might be daring but they aren't stupid.
Starc would be a good night hawk. I've always thought Cummins batting like he does in the IPL would make more sense then whatever timid rubbish he usually unveils in test cricket.
Maxi is definitely one that would add something, his bowling is a good addition too.
Cummins is a trustworthy bat in tests though for a tail-ender. Haven't seen him do anything similar in international white ball games like he did with KKR so far.
Yeah Labu being dropped is a bit harsh but him and Smudge seem too similar... I suppose the former can pull off a decent aggressive game too. I do think he's well overdue for a slide down, he's riding luck well beyond the 'you make your own luck' position.
Maxi used to be one of the best Shield batters back then too and unlike many T20 hitters of the times he was very passionate about wanting to play tests. Never got a fair chance even when the sandpaper saga was unveiled and never was taken seriously as a test batter despite it being arguably his best format. Pretty much any other side on the planet would have turned his undoubted talent into something useful but not the powers be in CA.