I've never played the game, but it seems as though the rules consistently refer to either "figures" or "non-hero figures". So a hero is a special kind of figure.
Some quotes from the rules:
During a figure’s activation, it may perform two actions. The available actions are Attack, Move, Interact, Rest, and Special.
A figure can perform the same action multiple times during the same activation except as follows:
- A non-hero figure can use only one of its actions to perform an attack per activation.
- A figure can perform each special action only once per activation.
Rebel allies are not heroes. During their activation, they cannot interact with crates or rest. Rebel allies can perform only one attack each activation, and follow all other rules for non-hero figures.
Some missions allow figures to retrieve specific tokens. A figure adjacent to or in the same space as the token can perform an interact to retrieve the token. Place the token on the figure’s base to mark that the figure is now carrying that token. The token now moves with the figure.
During a campaign, each Rebel player controls a hero. The word “Hero” is used to refer to hero figures, the player controlling the figure, and all of the associated components.
Since it says 'figures' in the piece about mission tokens, and does not exclude 'non-hero figures', I'd say a non-hero figure can collect mission tokens.