You can see the reinforcement number on both the trooper (3) and Tusken being (2) so I think it will be 2 troopers and 3 tuskens
Probably 3 and 3.I think the real question is how many of each will be in the box?
My guess is three raiders and four troopers
So from this page: https://www.fantasyflightgames.com/en/products/star-wars-imperial-assault/products/twin-shadows/
We get "With ten sculpted plastic figures, twelve double-sided map tiles, and over sixty new cards" so after the 2 heroes you're left with 8 baddies. So either we get one set of Heavy Stormtroopers and 2x Tusken Raiders or I think more likely we're going to get 2 sets each and they all are in sets of 2.