I was also thinking about a 'Card Driven" activation method, but that requires a lot of tinkering with the core rules and moving to alternate activations.
So something like a deck of cards. One for each unit. That you would shuffle at the start of the martian turn and then draw to determine activation order. Or possibly have a card drawn that determines the target priority for that unit to be plugged into the flow chart.
OR cards could be segmented with a section for each major type of Martian: lobos, assault, scout,. grenadier, special (harvester reaper, etc.). This would avoid having millions of cards on the table at one time. Some sort of activation priority number could be used (exact mechanics TBD), When the unit performs its action, turn the card face down beside the unit to indicate that it used its action for the turn. Take up cards at end of turn, re-shuffle, and deal again.