I agree with Mudflap. The assaults I've seen by the TR or VS that were successful all had a couple of things in common. One being air superiority usually through the use of Reaver packs the second being what appear to be organized packs of 3+ Prowlers and Magriders.
When they use their armor to the full effectiveness both TR and VS can blow over a continent rather quickly. I've seen it happen on Solsar many times. I think part of it comes from suprise factor. Seeing 5-10 prowlers coming down the road is something NC isn't used to and not used to defending against.
To expand on an earlier thought, every time I've had my ass kicked off of a continent in record time there has been one dominating factor: Air superiority. Yes you need ground forces to actually take the bases but if you can keep the skies clear and keep virtually any enemy armor from functioning while at the same time pressing the attack and utilizing your own armor units you've basically won the day. All that's left is the tedious step in between of actually taking the bases
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