I was picking a betta at petsmart yesterday and saw one is blue crown tail and it looks average size and swims very strong and seems very aggressive. One is halfmoon red and look much smaller and I chose it and put it in my 20 gallon tank and it has 2 mollies and 2 guppies inside it and all four disturb the half-moon a little bit yesterday but he still wouldnt flare. However after their first meal, they stop disturbing him and sometimes swim across each other without problem however the betta stills avoiding them and hanging by himself. So I'm asking did I make the right choice for getting the really small no flaring at guppies red halfmoon or should I have get the energetic, more aggressive blue crown tail.
P.s. I think the red halfmoon won't flare because it is so small (baby).