I'm not sure how you interpret this provision, but when it's stated in the plural, I think one can rightfully argue that it's a maximum of 10 minutes in total. In other words, 10 minutes are allotted for a witness; if there are two witnesses, then it's five minutes per witness; if there are three witnesses, then it's three and a half minutes per witness. I don't have a problem with that arrangement. If you wish to clarify that, by all means go ahead and do so.
