The point of ten, Wayfinder, is to mix-and-match. Let's face it, if you're talking about a multi-role stealth combat jet, he isn't shooting at just infantry on the ground. Also, you must not be looking too closely at some of the damage codes for launch missiles, I like the 22P of an AIM-27 Sparrow Hawk much better than the 16P of an AV missile.
He'll have some missiles / rockets / guns geared towards anti-infantry, possibly capable of dealing with light armor.
* Block 1 Mitsubishi-GM Outlaws
* LMG's with good AP ammo and tracers
* Mitsubishi Yakusoku MRL loaded with HE or Inferno
Additional hardpoints will be dedicated to AA weapons (better sensor and AP ratings than the anti-infantry gear).
* LMG's / MMG's with APDS or AV rounds... and tracers
* Mitsubishi Yakusoku MRL loaded with SAM AV missiles at high sensor rating
* Saab-Saaker AIM-27 Sparrowhawk with high sensor rating
If he's truly multi-role, then, in addition to those first two, he'll have at least two missiles / bombs that are mid-sensor, high-damage, high-AP or very heavy guns for taking on main battle tanks and other hardened targets.
* HMG's loaded with APDS or AV rounds... and tracers
* Assault Cannons
* Block 3 or 4 Mitsubishi-GM Outlaws
Yeah, you can mix-and-match ammo in a Mitsubishi Yakusoku, but that gives you damage codes in the 14P - 16P range. Since vehicle armor is hardened armor (SR4A, pg. 167, Vehicle Armor) I say "yes please" to any increase in either AP or damage I can get when going up against serious vehicles like fighter craft or MBT's (I know, no official MBT yet, but it's not hard to simulate one with a modded Roadmaster or Conestoga Vista as your starting point). This is where launch weapons come in, the weakest non-torpedo launch weapons match launcher-based missiles in damage. The rest exceed, by 2 - 6 points no less, the damage of launcher-based missiles.