Roy's our boy's our Roy's our boy's our Roy.
Super Mario Wonder I'd assume would be an option, but I don't know it well enough to suggest (Probably elephant form, but I can't tell what they'd use to represent other than Mario being big). But I want to mention Advance Wars, a game that got a release for the first time in 15 years after being delayed by one due to war. Considering this is a first time attempt for me to do one of these, it'll suck, especially representing the bomber.
Kanbei - Sephiroth? (Not one of the Sephiralts has black hair, this is not helping), stats raised for a time, I feel like the Wing could represent his counters being stronger well but I'm not sure how to represent that he's expensive.
Sturm - ROB with small Dark Samus minion, increased projectile damage, items dropped are firearm themed, calls on Moon Assist Trophy
Bomber - Meta Knight, plenty of bomb items dropping, including Smart, Bob-omb,
Submarine - Metal Inkling with Blue Steel gun, can get clear status regularly