She probably is continuing to research and develop weapons for the Chinese army, and doesn't often take to the field herself. Thing is, being the inventor of her power-suit and her giga-drill Earth Breaker (and both inventions being one-of-a-kind), she's the only one qualified to operate them, and I doubt she trusts anyone else to operate them, or develop them further for lethal battlefield applications. So, when the Chinese need job done that can only be accomplished by Yunru's power-suit equipment, they have to call her in as well.
Besides, it's not like she's going to go into direct combat; after all, she is a self-proclaimed pacifist, and she isn't equipped with any lethal weaponry, so she mostly provides support to other Chinese troops. For example, types of jobs she'll be called in to do:
- Neutralize Volkov and Chitzkoi (or other cyborgs) using her EMP/junk-data virus device; other Chinese troops can then capture or kill them with ease then.
- Provide support from the Centurion (a common tactic).
- Base demolition/sabotage with her Earth Breaker.
- Immobilizing a tank column within a thin chokepoint passage (EMP'd tanks at the front block the rest of the tank column behind them).
That said, I do think Yunru could do with a couple of additional abilities or something so she won't be so cripplingly specialized. If that's not possible, then at least some more opportunities in which she could prove useful (like, for example, in a commando mission in the campaign, have her do things like using her Earth Breaker to smash an ice sheet over a river to impede pursuing enemies, or break bridges for the same effect; another job she could do in campaign would be to immobilize an objective-critical vehicle for capture). Things of that nature should be included to showcase her possible uses, so people would be more likely to use her.
Edit: Oh, as for Siegfried: He probably wants to demonstrate the power of Einstein's Chrono tech for military applications (and the craft he uses is a one-of-a-kind prototype, not yet put into general production, so he's the only one who could pilot it). Also, being a patriot of Germany and the Euro Alliance in general, he probably wants to kill Commies himself - after all, "If you want Commies killed right, you gotta do it yourself" right?
Edited by WhiteDragon25, 13 December 2013 - 07:31 PM.
