The information in the GoAntiques site (as linked to earlier) is perhaps misleading in part. It states that Franco Toffolo was 'born in 1934 ... and worked for over 40 years in Venetian glass in Murano'. That would suggest he was in Murano until at least 1974. But he started the Venetian Glass Company in Blackpool, England in the 1960s.
There is also a bit of confusion on dates mentioned in the page on Franco Toffolo in the Scotland's Glass site
as it says he left Murano c1965 and his Venetian Glass Company was c1960-1980.
Assuming it is the same Franco Toffolo in all cases, I wonder whether at least some of his dancing figures may have been from his UK company and therefore not truly Murano (although made in exactly the same way). And perhaps that may account for the smaller sizes of some?
But this is not my area, so my thoughts are purely from observation of what has been reported elsewhere, not personal experience of these figures.