In theory yes, the GLA can build large forces quickly and cheaper. However their units arent as powerful. You'll need to micro-manage your battles well for them to work. Dont be put off the GLA though.
Some very general advice: make sure you set the pace. Dont let the game turn into your reacting to his actions. Mould the game from the outset by, as kbc suggested; attacking asap and not relenting.
Are you guys playing Zero Hour or the original?
Any way check out this program here:
http://www.hamachi.cc/download
It creates a VPN tunnel between your PC and other peoples PC; meaning they appear on a new local network. In that way; when selecting multiplayer in the generals screen, you can select LAN rather than internet. Not only bypassing the log in, finding the right lobby and passing your game so its private; but it also seems to improve performance.
Its very easy to use but here are some brief instructions:
1) Both DL the software
2) Install it. Run through the brief tutorial that pops up when you first install it. It explains things more concisely than I could hope to.
3) One of you will need to set up a network. Pressing the left alligned button, on the bottom right hand side (are you with me?
); select "Create New Network".
4) Set it up (very easy, needs a name and password).
5) Share the name and pass to your friend.
6) In the generals options screen; check that the lan IP address is set to the one created for the VPN.
Voila; network play possible with afformentioned benefits. Probably works in other games too. Excellant piece of software.