They may be able to speak English reasonably well, however they do not know how to teach, they are not qualified in anyway to asess the teaching abilty of any FT and submit teaching reports.

What you say above begs the following question. Who is qualified to assess the teaching ability of an FT in China? As you no doubt realize, the Chinese education system places its trust in its students to determine this. Many practising FT's know this too, and therefore try to become popular with their students by acting the goat rather than prioritize teaching them as well as they can. And who can blame any FT who decides to do so? Besides, the classes are by and large very overcrowded, and many Chinese students, the judges of FT's, do not wish to study English in any case.
I used to work for Yuncheng IELTS, and had a fling with two of the TA's there. Both of them told me in confidence that the headmaster, Mr River, a nasty piece of work, by the way, told all the TA's to monitor the feeling of the students re the teaching by befriending them. Whenever there was negative feedback, an FT would be fired, the excuse being made by Mr River that the Chinese teachers at the school where the FT was working didn't like him( or her)! You see, Yuncheng IELTS is extremely afraid of losing its contracts supplying schools with FT's, especially as there are also two other local Chinese recruiters after the business! Both TA's I was intimate with said that all the girls were threatened with dismissal if they got too close with any FT, and they had to report on the shortcomings of their FT's on a weekly basis. They were expected to be spies!

Maybe some of them really are beautiful, but an FT would have to be a bit hard up and desperate to marry a TA in my opinion. There are much better women out there.

Those TA's aren't all young women who can be manipulated by the headmaster. Some of them have their own minds, and realize that they have been unlucky enough to have ended up working there due to the very competitive Chinese labor market! I know of one FT who married one of the most beautiful ones. He teaches all over China, and she accompanies him. She is a farmer's daughter, but worldly-wise nonetheless!