Just get a hummvee in city map if your gdi.. In the beginning everybody says attack powerplant so what you do.
Get a adv engi. Get in the hummvee and take the closest way to the hand of nod. Now drive fast to the doors of hand of nod. If you did this right you didn't get shot by obelisk. Now drive on further next to the hand of nod straight to the airstrip and then right the obelisk. If you do this right you get in the obelisk with full health.
In city mostoftimes the weaponfac and pp gets mined first and everybody wants to destroy the pp so why not take the obelisk.