Preface: I love the Champion. I have been on record saying it is the Platonic Ideal of what a line cruiser should be. I doesn't need buffed, nerfed, or changed in any way...
...except for those silly Small Energies on the side that I have never used. They are an irksome blemish on an otherwise pristine hull.
Problem: The optimal use of the Small Energies on the side is to leave them empty.
The two Small Energies on the side have three strikes against them. 1.) Their firing arcs do not let them contribute to either the main frontal firepower nor do they protect the more vulnerable engines. The rear-most Small Energies already cover the 90% of their arc, so the side mounts are redundant. 2.) They're Small Energies: a topic unto itself but generally perceived to be one of (if not) the worst mounts 3.) Filling them with something actively robs OP/flux that could be better spent somewhere else.
Something like a Burst PD or PD Laser in those mounts aren't bad per se, but because of reason #1, all you're doing is giving token PD to the side of the ship that can't really double-up with the rear Small Energies all the way to the Engine. In a best use-case scenario, side-mounted PD protects the vulnerable flanks from a torpedo or pesky fighters. However, you're spending 14 OP for Burst PD and 8 OP for a single PD Laser that really can't do a lot on its own. Given that other Small Energies will draw even more flux (i.e. IR Pulse) or deal soft flux (Tac Laser) in a way that the forward battery can't help with, the awkward firing arc puts it in a no-man's land for the ship. As they are, leaving them empty seems like the best course of action.
Is there anything wrong with that? No, I suppose, but having mounts that are perpetually unused feels counter-intuitive. They do have a purpose, it's just that purpose doesn't compete very well against the other priorities of the ship.
Solutions:
Allow the firing arc to reach further back toward the engines:
If the side-mounts could "double-up" with the rear-most Small Energies more, I might be more tempted to utilize them to protect the sides/rear of the ship. I still don't know if I would use them for reasons #2 and #3 above. Making them face more forward, in my eyes, is bad since there are already 4 Small Energies up front that can handle PD-duty if necessary. I'm not a big fan of this idea but it's better than the current situation.
Change the mount type:
Things could get interesting here. For the most part, I dismiss out-of-hand changing it to Ballistic, Synergy, Composite or Universal because the ship doesn't have any already. From a hull design standpoint, they just don't fit to me. I suppose Synergy or Universal could work (as they don't take anything away) but that seems a little "extra."
Small Missile: This is the most intriguing as Small Missiles beg to be filled. It creates a bit more meaningful choice overall for the hull, though it would almost certainly have to be a guided missile of some sort. I'm wary about this option, however, because this is a straight-up buff to the Champion. A pair of Sabots, Harpoons, Atropos, etc. all of a sudden give it more flux-free punch. Alternatively, Salamanders or Swarmers give it some utility. The Persean League is also getting a bunch of new Missiles and as the premier line cruiser, it's odd that it wouldn't take advantage of that.
Small Hybrid: Take nothing away but add the option to use Ballistics here. They don't benefit from the ship system, just like the Mediums up front so there's still some choice here. From a ship design perspective, it tracks. That said, I'd take Vulcans over HEF PD Lasers any day. This at least alleviates any additional flux cost since Vulcans cost next to nothing to fire. You could, of course, throw some Kinetics/HE in there but again, the firing arcs don't allow them to contribute to the intended target up front. This is still a buff but not as much as having missiles. One could make the argument to change the Rear Small Energies to Small Hybrids as well for consistency.
Get rid of them:
Why even tempt us? I'm not keen on this option because even though I don't use them, others might. But if they were gone, they wouldn't be an OP-trap.
Overall:
I prefer the Small Missile route but I would understand why that's a bad idea. Technically, it also leaves the flanks even more vulnerable than before because you don't even have the option of putting PD there. That could be more of a feature than a bug, I suppose (i.e. "Champions are weak to being flanked"). If the side mounts were Hybrids, I *might* put Vulcans in there but I might still leave them empty because I prioritize the forward mounts so much more.