Maybe I am brainfarting here but I don't have my book handy and I am second guessing myself.
Isn't this army legal?
Horde Grunt
Horde Grunt
Horde Elite
Horde Individual
Apostle Grunt
Apostle Grunt
Apostle Elite
Apostle Individual
Apostle Individual
Common Support (justified by Horde Grunt squads)
Common Support (justified by Apostle Grunt squads)
The real question is about the second Common Support. Do apostle grunts only qualify for apostle support or both apostle and common?