Best answer
The Fused Tank is much more destructive and has better defensive capabilities than two separated tanks.
The player who requests the Fusion becomes gunner, with two new weapons. A plasma cannon that inflicts high area damage and a missile launcher that can hit 2 enemies at a time.
The pilot gets a shield that prevents all kind of damage to both players but drains energy over time.
The Health points of each player are added to one single Tank (including upgrades), that means double HP .