The Oath Keepers brought arms to DC for this rally they had a major hand in planning. That the FBI only seized one handgun from the riot doesn't by any means indicate or imply there were not other armed rioters, especially given evidence from chat logs and social media that these militia groups did travel with their weapons. And many of the rioters had non-firearm weapons as well (e.g., tasers, bats, crowbars, stunguns, knives, chemical sprays, etc.)
The reality is we'll never know the extent of how armed (guns or otherwise) the rioters were, because almost everyone was allowed to leave unimpeded.
Also watch basically any video reconstruction to see any number of people treating any number of objects like clubs. But I'm not going to rewatch the videos to find the timestamps. And now that I've jumped through your hope, I'll reinforce a key point: the vast, vast majority of rioters (both that entered and just lingered outside the capitol) were not searched.
The reality is we'll never know the extent of how armed (guns or otherwise) the rioters were, because almost everyone was allowed to leave unimpeded.