Can I satisfy stocking and schooling number requirements? (10 Gallons, Harlequin Rasboras and 1 Betta)?

I have an established 10 gallon tank with one Betta who has been in it for almost a year. He is quite mild tempered, and goes well with other fish. I've been looking for some community fish to put in with him, and have found that the Harlequin Rasbora species would be a great choice, not only temperament wise, but also because their water, temp, etc. requirements are practically identical.

My only problem is that these are schooling fish. From what I've researched so far, I'm hearing that there should be a minimum of 6 or 8 (I'm hearing mixed reviews on the exact number, so if you have an opinion on that I'd like to hear it). However, I'm concerned that 6-8 Harlequin Rasboras and 1 Betta (male, by the way) would be overstocking the 10 gallon.

Basically, I'm interested in knowing what you consider the minimum number of Harlequin Rasboras to keep together are, if I can fit that number in with the Betta without overstocking, and also if anyone has experiences they could share about keeping Bettas and Harlequin Rasboras together.