Trouble is, "having personality" tends to be a euphemism for "being an arrogant gobshite".
I prefer my sporting heroes to let their sport do the talking, and their "human side" to be manifested by modesty.
I wouldn't use the phrase "arrogant gobshite" to describe Ali. Clever, astute, witty, supremely confident, and self aware maybe. Sometimes, a sportsman has just got it, and you have to respect it. For instance, I didn't like the way Shane Warne went about his business, in his playing days, but I respected him and recognised him as a special talent. I also loved to watch him bowl. He was everything I hated about the Australian cricket team, but I could see that it was all part of his character, it didn't mean I didn't rate him as all time great. Sport would be so much the worse, if we didn't have people like Ali, Warne, Gazza, Bolt, C Ronaldo etc.