Smith's not a lock for ODI or T20 IMO - but could be in all three. Kohli would definitely be in all 3, AB has barely played a test so not sure you can put him in the test team except on reputation ? Starc could be behind a few in the test lineups too but in the discussion
de Kock perhaps?
QDK, Faf, Amla, Root, Stokes, KW, Boult, Shakib, and a generous shout to Mathews from SL, Dharwan, Sharma, Rahul, Pandya, are just so chopped and changed by India, but have great mutli format numbers of late. These are the arguable further candidates for discussion. But noone is really demanding for Sharma or Pandya's inclusion in a World Test XI today. Bumrah has only started tests now. There appears to be noone from WI. AFG will have high test hopes for RKhan (and Nabi). And of course Warner as I posted above.
Morkel may make his way back to T20 heights in the future, and Rabada may start starring more in the future. But they're not really T20 candidates at present. I think Rabada will definitely be in the future tho. He was more than useful to a star in WT20 in India and only 22 with so much cricket success under his belt already. He was dominant in the SA domestic T20 comp this year. But pretty ordinary in the IPL this year.
Mustafizur went off the boil in tests lately.