Rather than taking Gun Drones as wargear for Team Leaders, it can be a good idea to combine all those models into a squadron.  Gun Drone squadrons are fast, having Tau Jetpacks, and even though their BS seems low, they are more accurate than a Fire Warrior because the carbines they carry are twin-linked.

Gun Drone squadrons may Deep Strike if the mission allows it, which puts them in position to use their short-ranged weapons immediately, or even better, to target the rear armor of hidden tanks like Whirlwinds that do not require LOS.

Because of the Leadership penalties when the squad falls to less than four models, always take full squads of, which come in at under 100 points.  Cheap!

Pathfinders can be used many different ways and for many different roles.  Because of the required Devilfish, Pathfinders may be an expensive option for low-point games, and should be avoided in games smaller than 1500 or 1700 points.

An entire article could be written on Pathfinder tactics and the different uses for them and their Devilfish; and as this is an article about army selection, I will avoid their tactical implications here.

When taking Pathfinders, always take a full squad of 8, and consider including a team leader with Gun Drones to bulk out their numbers.  Due to their often advanced position, this is one squad I would suggest giving Photons to, to increase their survivability and buy them time for other friendly units to respond to the assault.  Always bond this unit, and the Devilfish needs to have Decoy Launchers.

  As it is a rare occurrence that enemies will flee from the Kroot in close combat, the Kroot Hounds are generally wasted points.  Unless you have 12 extra points, and no room for extra Fire Warriors or Pathfinders, I would leave these creatures out of my army list.  If the Kroot are used as riflemen rather than as an assault force (which they should be) Kroot Hounds with no ranged weapons do not add anything to the unit.  The points wasted on the Hounds could be better spent elsewhere in your army.