All of the named Galactic Republic Jedi have a leader ability, except for Ki-Adi-Mundi. Even the reworked Mace Windu kept his lead, and it is still extremely subpar. As such, there's no reason for Ki-Adi-Mundi to not keep with this tradition, and also have a lead.
Alternatively give him an Omicron Leader ability that will further boost Support/Healer Galactic Republic Jedi.
0