I played the mod till mission"one if by sea" before i stopped because i could not play any more. I like the ideal of the mod and how you were trying to tell the tale of the forgotten but it does not work out to well in mod.
Some of the problem come from foundation(tiberium wars)of the mod which dont show up as much in tib. game. As an example in "against the brotherhood" after i took the first nod base the attack from nods 2nd base were 5 planes 1 at a time and then 2 tanks 1 artillery rinse repeat. No other unit attack me till i went into 2nd base.
The other problem was ballance both unit and game. The first 3 units you could get horde,jeep and camper were to weak for the job and i found out by accident that the messenger was better at killing infantry the either horde or jeep. As for other it was what you faced example "against the brotherhood" in 2nd base there was atlest 6 air unit building their and my question is why so many❓.
So while there were some good parts in game as in use of buildings and some units overall it was like watching a movie with a great story line but bad actors.

I found that Red Zone mission oddly easy, especially compared to the previous missions and following mission.

Because the game can only see one subterranean tunnel network my Arteries of Assault got attacked, but the Civ ones did not. This let me blockade or destroy the bridges, expecting NOD to ramp up the attacks after losing a base, since the top right can easily drive over to the weakly defended entrance of the 2nd base.
Yes, this does mean you can access a subway from your network, but subway won't allow you to send in tanks, just send them out.

A few Slicers and Deployed Tick tanks easily used the bridges to eliminate all but the odd artillery or air unit.
I think part of the problem is the AI over-relies on the NE tib field, and any time it does that it over harvests it - this is what crippled GDI when I was stealing their tech.

The one after it, against GDI and NOD (and NOD I think) is insane in comparison. They were sending APC round the back to hide the 5+ Railgun Predators they were sending in from the west. And it was their first attack.
All NOD had sent was a few infantry and light/med vehicles.

Hi scifi i was not saying it was hard was playing on med diff. but was saying that the ai got dumb after i took the first base it would not use any more units then what i said. Maybe it was relying on ne field which means that there is still a problem with game because it should have had more then enuff cash to do more.