Here are the best-on-best international tournaments numbers of the new available players. Again with a focus on the knockout stage but also taking the overall numbers into account.
Malkin
Olympics 2006: 2 gp, 0 g, 0 a, 0 pts
Olympics 2010: 1 gp, 0 g, 1 a, 1 pts
Olympics 2014: 2 gp, 0 g, 0 a, 0 pts
World Cup 2016: 1 gp, 0 g, 1 a, 1 pts
Total at best-on-best tournaments knockout stage: 6 gp, 0 g, 2 a, 2 pts
Total at best-on-best tournaments overall: 20 gp, 7 g, 11 a, 18 pts
Dionne
Canada Cup 1976: 2 gp, 0 g, 2 a, 2 pts
Canada Cup 1981: 2 gp, 1 g, 0 a, 1 pts
Total at best-on-best tournaments knockout stage: 4 gp, 1 g, 2 a, 3 pts
Total at best-on-best tournaments overall: 13 gp, 5 g, 6 a, 11 pts
I would say that Malkins overall best-on-best numbers are strong. His scoring at the knockout stage is at least somewhat underwhelming though and because of that I don't think that Malkins best-on-best resume quite measures up to that of Tretiak or Forsberg.
Dionnes numbers both overall and at the knockout stage are rather average for a player of his quality when taking into account that he played in a very high scoring era and I would probably rank his best-on-best resume last of the available players.
Tretiak
Forsberg
Malkin
Dionne
Tretiak
Summit Series 1972: 8 gp, 236 saves on 267 shots, 0.883
Canada Cup 1981: 2 gp, 52 saves on 54 shots, 0.963
Total at best-on-best tournaments knockout stage: 10 gp, 288 saves on 321 shots, 0.897
Total at best-on-best tournaments overall: 19 gp, 524 saves on 577 shots, 0.908
Forsberg
World Cup 1996: 1 gp, 0 g, 0 a, 0 pts
Olympics 1998: 1 gp, 1 g, 0 a, 1 pts
World Cup 2004: 1 gp, 0 g, 1 a, 1 pts
Olympics 2006: 3 gp, 0 g, 4 a, 4 pts
Olympics 2010: 1 gp, 0 g, 1 a, 1 pts
Total at best-on-best tournaments knockout stage: 7 gp, 1 g, 6 a, 7 pts
Total at best-on-best tournaments overall: 22 gp, 3 g, 18 a, 21 pts