Relationship between SharpP-measure and SpanP-measure

Ascertain whether there is any general implication or separation between SharpP-measure and SpanP-measure; specifically, determine whether mu_{#P}(X)=0 implies mu_{SpanP}(X)=0 for all classes X, or vice versa, or exhibit classes that separate these notions.

Background

Counting measures defined via #P- and SpanP-based martingales sit between P- and PSPACE-measures. Although #P is a subclass of SpanP as counting classes, it is not clear how their induced measures compare.

Understanding whether one counting measure dominates the other would clarify the hierarchy and applicability of counting martingales.