Cyrillic fita writes the same borrowed Greek letter for the same purpose and takes the numeral nine, which is the value of Greek theta. Glagolitic gives it no value at all, having stopped counting several letters earlier when its own sequence ran out.
That single difference sums up the two numeral systems. Cyrillic numbers by asking what Greek letter stands in the slot, so a letter borrowed directly from Greek naturally keeps the Greek number, wherever in the Slavonic order it happens to sit. Glagolitic numbers by counting its own letters from the beginning, so a letter that falls after the twenty fifth position gets nothing, whatever its Greek ancestry. Two different questions, two different answers, and the same letter.
The letters that serve Greek spelling rather than Slavonic sound are the small group in which a derivation from Greek is not in dispute. Whatever is decided about the shapes of the Slavonic letters in general, this sign answers to Greek theta by function, in both scripts, and the atlas records that correspondence as attested. The separate question of where the Glagolitic letterform came from is recorded separately and marked debated, because the two questions have different answers and different evidence.