Conundrum

Here's a question I can't seem to get a straight answer on. You go to a Mass. There are maybe 50 people there. Anywhere from 8-10 serve as Extraordinary Ministers of Holy Communion. Ignore the violence done to the word "extraordinary" in this case.

Here are the guidelines for EHMCs:

In every celebration of the Eucharist, there should be a sufficient number of ministers of Holy Communion so that it may be distributed in a reverent and orderly manner... If such ordinary ministers of Holy Communion are not present, "the priest may call upon extraordinary ministers to assist him, i.e., duly instituted acolytes or even other faithful who have been deputed for this purpose. In case of necessity, the priest may also depute suitable faithful for this single occasion (GIRM 162)..."

When recourse is had to Extraordinary Minister of Holy Communion, especially in the distribution of Holy Communion under both kinds, their number should not be increased beyond what is required for the orderly and reverent distribution of the Body and Blood of the Lord...

In my experience, if you ask folks why they have so many EHMCs at such a Mass, they will usually not offer the above rationale. Instead, it will generally be because they want "the lines to move faster" so that "people aren't just left sitting there waiting on everyone else."
Regardless of whether that conforms with the cited material, has nobody noticed that the purification of the sacred vessels takes longer than if the priest had to give communion to the whole parish? Today's example was worse than usual because of the 8 participants, I think 6 had chalices. Every time the priest turned around, somebody was setting down another chalice for him to clean.

Anyways, just a musing from past experiences and an inability to understand how this keeps people from sitting around and waiting.