Cyrillic dzelo writes the same affricate and stands in the same place, and the two alphabets number it differently in a way that is more interesting than the usual offset. Glagolitic gives it eight by counting its own letters in order. Cyrillic gives it six, and six is a Greek value that belongs to no letter of the classical Greek alphabet still in use: it is the slot occupied in Greek numeration by the old sign for the sound that had dropped out of the language, kept in the counting even though it was no longer a letter anyone wrote words with.
Cyrillic therefore did something more than copy the Greek values across. It fitted a Slavic letter into a gap that Greek arithmetic had left behind, which shows the system being adapted rather than merely inherited, and it means the Cyrillic numeral for this letter is evidence about how carefully the arrangement was made.
The names agree in both alphabets and the sound agrees. What separates them, once again, is the shape and the arithmetic, and those are the two things on which the argument about the relationship of the scripts has always turned. The atlas records the pairing as a correspondence of sound, name and position, and leaves the direction of descent open.