Actually UA is better if it is compare with CO, as CO doesn't even have a base in Asia, they just rely on the single language FA on each flight that base in EWR/IAH to do their job.

I did EWR-HKG-EWR, so the laguage FA is a mandarin speaker, she speaks so fast I have no idea to catch on what she is speaking at all. I felt bad for those cantonese speaking people that speak very little english, they just not able to understand any announcement at all. UA however there are always more than 1 language FA on board, as they always use mix bases FA on each flight, like HKG base will fly all those routes out of HKG and beyond, they always change the ratio like HKG will do HKG-ORD for a month, then vice versa. But even without the HKG base, SFO base will have more FA that is able to speak cantonese or mandarin.