Why a Stryker formation needs mobile direct fire

Was the Stryker Mobile Gun System forcing a wheeled armoured carrier into the role of a light tank?

A direct-fire vehicle that can keep up with a Stryker brigade has a useful role against prepared positions; mixed wheeled and tracked formations face different mobility compromises.

Prepared defensive positions give a wheeled formation a reason to carry its own direct-fire weapon. Using a Stryker chassis lets that weapon move with the rest of a Stryker brigade. Mixing wheeled and tracked vehicles creates a different problem: the formation can lose the wheeled vehicles' road-mobility advantage while remaining constrained by their more limited cross-country performance. Wheels can handle some of the same terrain as tracks, but the comparison is qualified rather than treated as universal equivalence. The defence of the gun vehicle concerns its formation role and mobility.