Seicercus Warbler, Guangxi, Question (1 Viewer)

This morning I observed a Seicercus warbler amongst a group of birds in Baise, Guangxi, China. Being to the ID of Seicercus, and seeing that they are quite difficult to ID without vocalizations, I wanted to ask what species are potential in this area at this time of the year. Here are the things I observed:

Bright yellow underneath extended all the way up throat to bill. Face not strongly set off, but not as bright yellow...more greenish. No noticeable wing bar. Head with black lateral stripes, not visible from side view or underneath. Undertail mostly white. Very active in feeding at low-mid story in trees.

Thanks!
Mike W.

structure of eye ringed is quite usefull as tephrocephalus has a broken eye-ring at the rear (slightly broken) and affinis on the half top at the rear.
I guess that you could expect 5 species : affinis, valentini, soror, tephrocephalus and omeiensis....

personally, I've been abble to ID only affinis (1 time), and soror wich is quite common in spring in Guangxi...

Vocalisation is as you said by far the best to get throught these...

All the best,

Jonathan