If I'm gonna bring eggs to a field, by COD, I'm gonna use 'em on the strats (fuel, ammo, dar, barracks) first unless we are on the verge of capturing the field.
Its always useful, to ask for a sit rep at the field you are going to. If your team is on the ball, they'll TELL you what needs to get hit. If you don't get a reply, ask again (no CAPS) and if you STILL get no reply, hit what ever you want.
Nothing gets my panties in a bunch more than asking for a sit rep on a field that is covered by teammates, not getting one, then after destroying something on the field, getting yelled at by said teammates for destroying it.
DO NOT base your decision on what to hit by how many friendlies are over the base. If its standing, and no one is calling "troops out" hit it.
People are gonna squeak no matter what you do. Its a game, do what you can to help your team, in abscence of that, fly for yourself.