Different system has different set of Jibengong. If you cross train many styles, you may have problem to find enough time to train all the Jibengong that's needed. If you don't train the Jibengong for a certain system, you are not truly cross train that style.
Here are some Jibengong for SC. If you don't devoted your training time into it, you will never be good in SC (you may just touch the surface of that system). You also need to spend time to maintain it. Without daily maintenance, your will lose it.
http://v.youku.com/v_show/id_XMzQ4MzQ2MDQ0.html
I don't know how MMA guys may solve this problem. I'm sure boxing, MT, wrestling, and BJJ all have their special set of Jibengong.