oh sweet thats good to know i appreciate the feedback. Ill have to try haveing the medic in a squad and the rest as specific to their defenders
here's
an article about healing if you're really interested.
the bottomline for my thinking is that medic 3 rocks since it heals all units in the same or adjacent tiles 25% more than they'd heal on their own. this applies only when the other units don't move (which includes no pillaging) of course. the medic 3 can in fact heal them (but not himself) if he moves, even if he doesn't have march. keep in mind that all mech inf start off with free march, so i rarely use any promote attacking units that direction.
as carl said, you don't want the medic fighting/defending at all, he's pure support. so i put medic 3 on a *very* weak unit and never upgrade him. it's a waste of the "free upgrades" feature of the GG but i consider worthwhile, i do it early on (usually my first GG) and benefit game-long.
a note about siege weapons: four current-era cats/cannons/whatever with the accuracy promotion can get any city's defenses down to zero in one turn. you can get acc by going bombard 1 -> accuracy or CR1 -> accuracy. if i have siege weapons i dedicate 4 (or 8 for two SoDs) for bombard+accuracy and don't attack the city with those guys. i promote the others (including replacements made during the war) with the CR line. i love when attacking cats i was sure were suicide retreat, exp yay!
agreeing with a-f-n-k once again (is it okay to call you that? do you prefer ankh? i'm lazy), early on i like to get a couple horsemen Sentry. this is particularly helpful with the fact that for medic 3 healing the hurt units need to not move, and some will be outside your new city, at least one will be inside. sometimes sentry gives insight into whether resting a turn is safe.
i love playing with promotions. it's a fun aspect of the game for me and as you learn/experiment with that, it will add to your military success and the fun you have.