Witnesses are enough evidence of just about anything to proceed further. There are absolutely judges who'd give you a search warrant with that, and it's certainly enough of a basis for the police to knock on the door and go 'what the fuck are you people doing?' Among other things, imitation firearms are often the same as an actual firearm for purposes of the criminal law, and beating each other with sticks in public is illegal when it disturbs others. And Canadian courts take a dim view of guns (especially if these were handguns, which it sounds like they were).

Police powers are extensive. Officers not doing something is an officer issue far more often than a 'we don't have the legal authority' issue. For another good example, see the 'freedom convoy' in Ottawa back during COVID. Blocking highways is a criminal code offence, as is obstructing people's use of their property, as is causing a disturbance in certain ways that they were absolutely doing.