I think it would be crazy to not import all of C1 into N4. Some things may get more complicated, some units may get extra skills and equipment but no base rules will be different. For example, the bonuses on MA won't change, but level 4 and 5 might get extra abilities like they had before. On a slightly different topic, some of the costing still needs a little work in C1. Zanshi doc/eng costing the exact same as a regular zhanshi seems odd. Jujak BS and Jujak CR/HFt both cost 2 but the Zuyong BS costs 2 and the Zuyong CR costs 2.5. Internally to each unit it makes no sense to me and outside the unit, the Jujak CR is cheaper than the Zuyong CR and it comes with a free HFt.