My 200L tank currently has 2 gouramis (can be occasionally "pecky", but
only ever to each other), 8 neons, 1 pl*co, 5 zebra danios, 3 siamese
flying foxes, 3 platys and a swordtail. It's quite heavily planted, and
has lots of hiding places.

Gouramis are notorious betta harassers, and in betta vs. gourami the betta
usually loses. The platys might want to play too much nip-the-fin with the
betta, and male bettas will sometimes attack platys. I don't think this is
the right community tank for a betta.

In my experience it's a coin toss as to whether or not a betta will do well
in a community tank, anyway - some do fine (many of mine have co-habited
with swords and guppies and they pretty much ignore / avoid each other) but
others really just prefer to be alone. I once had one that had the guppies
so scared that they stayed huddled over against one side of a 10-gallon and
the betta ruled the other 2/3 of the tank in solitary splendor. I moved the
betta into his own tank and it was still a full day before the guppies
calmed down enough to move around.

Then there was sort of a fry explosion. All those weeks of terror and
pent-up frustration, finally released...

--
John Goulden
mostly goldies, guppies, swordtails and bettas