It's like with swim checks; they don't typically need to make checks except to avoid a hazard or when otherwise distracted, but get a +8 in such cases, and can always take ten. I think. Anyway.
Here's what the warriors of the 'Mount should be kitted out like. Just roll with the templates; the sheer number of kobolds should mean that they should be able to find them(also, dragons can shapechange, which is where half-dragons typically come from). This is not perfectly optimized(that requires Strongheart Halfling Crusaders interspersed with Water Orc Barbarians and Wood Elf/Catfolk Warblade/Swordsages(if they can do ranged stuff with their maneuvers; otherwise, fighters or rangers would be more appropriate), and really, such a group should be at level 3-6 on average to represent their elite tactics and ability to survive countless battles.), though.
Kobold Phalanx:
First Rank: Draconic Kobold Fighter 1(really it should be Crusader for true effectiveness, but the fluff behind that really doesn't help.)
Stats(Elite Array): Str 13, Dex 16, Con 13, Int 12, Wis 12, Cha 10
Feats: Swarmfighting, Phalanx Fighting(more can be added, if flaws or something are used, but these are all that's really needed)
Equipment: breastplate, heavy wooden shield, handaxe, 3 javelins, sling, sling bullets (10)
Fort: +3 Ref: +3 Will: +1 AC: 26 (+1 size, +3 Dex, +5 natural, +5 breastplate, +2 heavy shield) Touch: 14 flat-footed: 23 (Their AC becomes 29 in formation)
Attacks: handaxe +2 melee(+5 in formation) (1d4+4/x3) or javelin +4 ranged (1d4+4) or sling +4 ranged (1d3+4)
Second Rank: Half-Dragon Kobold Fighter 1
Stats: Str 19 Dex 16, Con 10, Int 13, Wis 12, Cha 10
Feats: Combat Expertise, Improved Trip
Equipment: breastplate, guisarme, buckler, flail, 3 javelins, sling, sling bullets (10)
Fort: +2 Ref: +3 Will: +1 AC: 22 (+1 size, +3 Dex, +2 natural, +5 breastplate, +1 buckler) Touch: 14 flat-footed: 19
Attacks: guisarme +4 melee (1d6+6) or flail +5 melee (1d6+4) or javelin +4 ranged (1d4+4) or sling +4 ranged (1d3+4)
Archers: Draconic Kobold Fighter 1
Stats: Str 13 Dex 16 Con 10, Int 13, Wis 12, Cha 10
Feats: Rapid Reload, Precise Shot
Equipment: studded leather, buckler, mighty heavy crossbow(+1 Str), bolts (20), sling, sling bullets(10), spear
Fort: +2, Ref: +3, Will:+1 AC: 19 (+1 size, +3 Dex, +2 natural,+2 studded leather, +1 buckler) Touch: 14 flat-footed: 16
Attacks: heavy crossbow +4(plus additional possible bonuses) ranged (1d10+1/19-20) or sling +4(see previous) ranged (1d3+1) or spear +2 melee (1d6+1/x3) or spear +4 ranged (1d6+1/x3)
And then various support staff. Bards, sorcerors,etc. Second rank could have swarmfighting too, instead of being half-dragons(draconic is easier to find, is my reasoning).