I would say really the only benzodiazepine that is close to the potency of Brotizolam would be Triazolam. That is prescribed anyways. As they are both 0.25mg ~= 10mg Diazepam.
Going on the parent drug (Probably a more elegant way of saying that) Clotiazepam's doses are around ~5-15mg's. Though an interesting thing I found.
Not sure how much you can extrapolate from a "normal" benzo to a triazolothieno though.
My guess would be that thiophene v. benzene fused to the diazepine doesn't make much of a difference, unlike the replacement of the oxo- and N-methyl groups with a triazole ring. Alprazolam, the triazolo version of diazepam, increases potency by a factor of 20, drastically decreases its half-life and makes it act primarily anxiolytic. Diclazepam, the 2'-Chloro analogue of Diazepam, seems to share its parent drug's balanced action, while increasing its potency by a factor of ten, and moderately shortening its half-life.
Now, Triazolam (2'-Chloro-Alprazolam), when compared to Alprazolam has about 2 times the potency, only about 1/3 of the half-life, and most interestingly a primarily hypnotic effect (cf. Etizolam, which despite the 2'-chloro is still more of an anxiolytic - would that be an effect of the thiophene, the ethyl on the thiophene, or a combination of both?).
I guess to make more accurate predictions about future triazolothienos we would need more comparable triazolos to be synthesized: For example Phenazolam (7-bromo,2'-chloro) to compare with Brotizolam, or a 7-ethyl,2'-chloro triazolobenzodiazepine (Eclozolam?) to compare with Etizolam.
...come to think about it, it might be interesting to compare Alprazolam and Deschloro-Etizolam. Not all that many reports on the latter, though it looks like it has a longer half-life and lower potency than Etizolam.
...oh, and I see they recently released Bromazolam (the bromo-version of Alprazolam), which is supposed to be longer acting, less potent and more sedating than Alpraz - might be another interesting piece of the puzzle.
tl,dr; Someone make Phenazolam, so we can compare it to Brotizolam.