Yep, Chinese teaching assistants mostly have poor English skills. That makes it easy for a native speaker of English to moderate their bossiness. Also, they're usually disloyal to the agent whom they work for. That's because they're only on about 2,000 RMB/ month at most with no long-vacation pay. They resent their employment package even more when they compare it to what an FT makes. Fact is, the turnover rate among them is very high. Few last more than 5 years in the job. They will either marry or find a higher-paying job during their time as TAs. But they can make an FT's teaching job much easier at a state high school in two ways:
1) by being an interpreter
2) by maintaining discipline

It makes me laugh whenever posters berate Chinese TAs. Last time I taught (maths) in the UK, there was a special needs teacher with me for my first year secondary school students at the comprehensive school in Tobermory. I was a supply teacher. That was some years ago. There were only 21 students in the class.
Real teachers know that a teaching assistant can make the subject teacher's job much easier! But in China, most EFL teachers aren't real teachers. And those that berate TAs haven't ever been certificated practising subject teachers back home in the west. They don't know what they're on about!

There you are, from the pen of a properly qualified teacher, who didn't just come to China because, like me, it's a great place to be, or like most other FT's, no other bugger would have him. No no, it was a genuine choice for him to teach in China. The only way a precious few of us could teach in the UK would be to try and get a position as a TA- most of us would be laughed out of the door entertaining that degree of megalomania(Ooopos can't really say that can I? was that an oxywotsit?)

If I wasn't able to handle a young TA, I would be too embarrassed to admit it. I myself have been able to make their lives a little sweeter. They can be like a pit bull terrier in defence of their FT's....but, you only get out what you put in.