zocom are somewhat underpowered. they have like only 2-3 ways of winning. There best way is the super predictable ZR+HH+Ap ammo+Ceramic armour which has quiet a lot of counters, 2 storm columns and 12 of those Zonehead are dead. Or some venoms and it's over, and so on. another way for them to win is an early game infantry 'push' meaning waves of infantry while doing dig in and pushin' forward and bringing newer tier infantry and vehicles in aswel.

Oh and to answer your question, no zocom are not supposed to be the future GDI, they're the anti-tiberium GDI and are introduced in act2 meaning they were part of the third tiberium war aswel.

wikipedia says it's the future but when playing the campaign and reading the intel it's obvious that it's just a high-tech corporation and part of GDI that is on a mission to stop tiberium not to do with time.

rail guns were taken away to balance the game and basically ZOCOM work with sonics and weren't exactly meant to be a war based faction of GDI and then their sonic tech turned out as a decent attack and defense too. So they don't use rail guns.

As for Zone troopers vs Zone raiders I'll give my vote to Zone raiders, let alone they have AA capabilities, they're better at destroying buildings, and their attack against vehicles is Area effective so they can destroy 2 scorpions at a time. In bigger numbers Troopers seem a bit better than before first of all they don't suck so badly against buildings like they do in small numbers and they also seem a bit better than zone raiders against vehicles. But it seems that the advanatges the zone raider has are more but don't forget they both suck big time against infantry so I always carry a commando with them.

as i said at my 1st post, an infantry "push" is one of zocom's ways of winning. Although you must definately have APCs, riflemen, missle squads and Pitbulls aswel. Riflemen have the dig in ability so you can aswel have a chance of continuing their push, missle squads are needed for AA and AV especially early on. APCs help for AA and garrison slot. Pitbulls are an all-round unit mainly for some scouting. Don't forget to give AA support, 3-4 hammerheads/Venoms and your whole beloved army is dead (there's a reason I reccomend missle squads and apcs.)

I beat a brutal AI using infantry push, (I don't call it rush because in my tactic, you keep sending reinforcements and sometimes you keep back for a moment) you just need to be quick and be tactical, a foxhole with 2 riflemen squads is a deadly place for the enemy who foolishly loses 6 of his squads.

I've told you before about this infantry push. It owns! Just keep using the dig in ability and you shouldn't have any problems. Base Defenses are not to be concerned really, at that stage the enemy is weak and you shouldn't attack in a rush, you can simply call in more ZRs and at then firehawks with stratoboosters and ceramic armour can EASILY finish off anything.

And the thing is, I've done this tactic many times so you can be sure that this works.

Nah why should I be offended?

Trust me get 4 riflemen with as many missle squads early game and harass his economy by using foxholes near tiberium fields, it's just laughable how they lose harvesters big problem is black hands because they're very resistant and clear building but you still can use it against GDI and Scrin.

well there's a couple of things that makes ZOCOM better for this:
1. Tiberium suits
2. Zone Raiders
3. Hammerhead gets ceramic armour which means less risk of putting infantry init.