I think all policemen should work in teams with at least a protocol immobilise an assailant by gunfire, by other policemen on behalf of the policeman the assailant is attacking or facing, vz discrete hand signals after the taser is used (tasers should be used with less hesitation if assailant is armed).
E.g. A verbal or physical hand command would be a command to shoot at the leg because the facing policeman (preferably the team leader who has since drawn the armed assailant's attention) feels increasingly unsafe or that gunfire is needed to immobilise the assailant for minimum overall bloodshed. One or more shots may be fired, depending on how dangerous the situation is or how much the controlling policeman is requesting, suffice to say, in an open area, there is more than enough opportunity to target the assailants legs, whilst the lead (targeted) policeman still retains the option of firing point blank if these leg immobilisation protocols fail.
Such an fire upon command would be a great show of team coordination and force, which would remind the assailant that he is facing a capable team of policemen and that the policeman he is targeting doesn't need to fire his own weapon for an escalated and progressive takedown by gunfire.
Too many times, targeted policemen have shot assailants in the chest using self defence as an excuse, but given significant superiority in firepower and numbers, self defence is a weak and tenuous excuse. Could this be an discrete eugenics national protocol to eliminate citizens which the state deems unfit, or to silence the assailant, because the dead cannot speak for themselves?
Hopefully, the police have a proper protocol to improve the survival of assailants, especially those facing mental stress and are unable to control themselves. They have a right to medical treatment and a chance to turn over a new leaf. There should thus be more efforts made to immobilise assailants, rather than shooting them dead.
AFAIK, all policemen patrol in pairs, so there has to be some coordination between the pair about the stepwise use of force to neutralize a violent assailant, with minimum blood loss. In due course, or by bystander video recordings, society will demand that the video recordings are made transparent vz publicly accessibility to view. The number of people shot dead by policemen vs the number of cases involving police gunfire should also be recorded and audited through the years as one indicator of protocol quality and service performance measure.