mixing different barbs

i currently have 5 gold barbs(Barbodes semifasciolatus) in my 30 gallon planted tank; i'm planning to add 5 odessa barbs(Pethia padamya). The internet says both types can reach 2.8 inches, but the average size is below 2 inches. Some questions:

1. i read that barbs like to school with their own types; if i add just two odessa barbs, will they school with the gold barbs? Or will they count gold barbs as "different", and possibly become nippy/aggressive?

2. The internet says both types can reach 2.8 inches, but usually they don't grow beyond 2 inches. That said, can i add more than 5 odessa barbs?

tia