Good combination of weapons used by our forces from 1989 to the present.
I remember we carried Mossberg 500s around in Iraq (2003); got those fresh out of the box, along with basic M4 carbines (no rails, no optics and had the older CAR “fiberlite” stocks) and M249s. We did not get the KAC QD mounts for the M203s, so our squad leaders had M16A2s with the '203s mounted.
Gecko should also include M4A1s with M320 GLs, M240Ls, M32A1 RGLs and Mk47 Stryker AGLs on another set; maybe a “Modern Special Forces Weapons” set, along with the weapons @Trisaw mentioned.