I'm not entirely clear on what you mean. Do you mean each of his bodyguards become a special HQ unit? They're just Shas'vres iirc, so I'm not sure they each deserve a place of their own, over say, a Cmdr Brightsword or Shas'O Ry'mr
If you mean just giving Farsight's Shas'vres more character, then I think that's a good idea. Same with the idea of making them squad leaders. Each approach would mean totally different approaches though.
I'll just throw out some ideas on keeping them a single unit of 8:
Give them all vectored thrusters, including Farsight. 5th ed made the ninja'o what it is today, and Ninja Tau players deserve a special character to represent them. Since he's a special character, he's allowed to be OP'd. He can have the +1500 pt stipulation and stiffer list restrictions to keep non-Farsight Ninja lists viable.
^I think this could really work, with all the things the Space Marines got. Yes, this unit would become a substantial cc unit, but Farsight lists won't have any Kroot whatsoever (or they shouldn't in this incarnation, if they do right now). Farsight's buddies would still be more-or-less regular Shas'vres (iirc) anyway in terms of stats, so it wouldn't be gamebreaking, right?