This is incorrect. Our muscles fire in a mosaic pattern, not as fascicles. Fibre type grouping occurs in disease and aging when muscle fibres lose innervation and become reinnervated by near neighbours resulting in the regional firing patterns you describe.

Edit: an advantage of mosiac firing pattern is that it spreads the stresses across the muscle rather than generating regions of high local stresses. Fascicles (i.e., the perimysium) help transmit the stresses from fibres to tendons.