Those bosses' mental unpreparedness, along with Trump's abdication of CiC help, caused much of the rest of unpreparedness.
Those bosses acted like bureaucrats, being uncommunicative to the 3 here about the FBI's intel. They all said "No." to the question of whether or not they got the FBI intel from the night before.
Bad judgment by the bureaucrats who interface intel with on-the-ground forces.
So they all ended up failing to judge the crowd and the planning behind it, because CPD's terrorism joint task force squashed the FBI's Jan 5 intel.
So, because "normal" advance procedures were in force, not "emergency" procedures, they failed to harden the perimeter, arm the CPD personnel, and being embattled and injured after at least four hours, failed to make arrests.
That's the way I see it. The whole FBI to JTTP to CPD uses too weak a chain of information -- too many bureaucratic deciders -- to act to prepare on-the-ground operations appropriately. Which isn't noticed until a severe riot crowd shows up. And even then, no new Plan B of operational forces are sped up to surround such a riot crowd and detain them for interrogations -- no Nat'l Guard deployment, no arms distribution, no buses for rounding up rioters, etc.
If the funders and enablers of these rioters had known more about CPD personnel, they might have somewhat succeeded in their desired takeover of democracy.