So I got them both dewormed again today.
And I found out today that Bandit and Xiao Li are actually not from the same litter. That accounts for the fact that they are of a different size.
Bandit and Teddybear (now with Ramzee) are from one litter.
Xiao Li, Bobtail (now with Ramzee), Wolfie and Simba (now adopted by Daniel) are from Khine's own mother-cat.
The clinic had paired them according to their state of health. Both Bandit and Xiao Li had eye discharge. Hence, they were put together.
Anyway, they seem quite comfortable being together now.
Both are up for adoption - but I'll take better photographs next week.
I'm dead tired right now.