It depends my one betta, Romeo, loves his two cory cats and hates only neon tetras but will let guppies and even gouramis swim around him. My other betta, Fade, hates everyone and everything expect me. See bettas are like cichlid individuals. Only thing I would worry about is that gourami with bettas cause they are close cousins and sometimes fight. I say go for it but be careful. Honestly a hit or miss.