It says specifically under grapple (P. 156 phb 3.5) that ties to go to the person with the highest modifier, with a reroll in case of that being a tie.
On page 104 of the DMG 3.5 under Cohorts, first sentence second paragraph it states that there is no limits to the number of cohorts that can be employed by a character. The text for attracting cohorts and the leadership feat on page 106 goes back and forth between using verbiage that states or...