Given GW is lame and gay, I've thought up of something that would allow armoured spearheas to be playable

let me know what you think
>Master of armour is high command slot unit, and must be upgraded with a decurion, he gains +1 BS and a 5+ invun
>if he's your high command, tanks upgraded with decurions become command slots

something simple, with the decurions serving as a "forced upgrade" if you want more detachments but still want tanks