I'm playing on Normal. I have to say that it's not any exact problem I'm having. Instead I just do not seem to have the patience for mauling the Temple.
If you do decide to got through the mission for me, then I do thank you. I just don't know what kind of help I would need. The worst problem I seem to face currently is that of defence. The AI is rather nice for an RTS and seems to look for holes in my defence, which means that if I a) make the initial base more central on the map and circle the tib field with it in order to protect my economy, there's soon rocket militia and fanatics sneaking in the back and I have like three directions to defend, but if I b) make the base to the edge of the map, nod armour attacks my harvesters constantly.
I'll try the firehawk strategy once I'm home, it sounds like something I should have come up with. Maybe 8 firehawks to start with, and once most of the facilities are down, ergo the tide of black hands is down for the moment, bring in the death metal. I have a central base save where the situation isn't too dire yet(no shadows yet), but there I haven't taken the northern tib field though. Will probably restart. The pen them in -idea is good as well, with some Rigs, as it would move the fighting away from the tib zones and my bases.
Edit: I can't believe I'm this stumbled on a C&C game. Well, just about a whole new dev team and all, but still...