For starters the issue isnt with police being heavily armed it is with them not being held accountable then they use it. Them like thr citizens can and shouod be as heavily armed as they wish as long as they are responsible and accountable to their actions.
Second, the disparity in armament seems to occur in coubtries with strict gun laws to a greater extent not lesser. I the usa for example police and citizens are fairly equally armed, in the UK however certain police are allowed to be armed while the citizenry in general more or less cant be, showing a greater, not lesser, disparity.