So, first off, I'm going to say that this matchup basically comes down to how much you respect staff utility. The two have comparable player phase offense, and Homeros has all of 3 chapters extra availibility, but Sara has A staves post-promo and Homeros has D, compared to Homeros being able to occasioanlly have an enemy phase if there aren't too many enemies.
So, the comparison. This is taken in like mid-chapter 18, since Sara levels like a truck.
Homeros 10/4 (alternatively just level ~16-17, but sage promo bonuses are sexy)
29 hp, 14 mag, 15 skl, 20 spd, 7 def, 16 luk
Support from Nanna, no combat skills
Sara 10/1
15 hp, 19 mag, 19 skl, 16 spd, 3 def, 11 luk
Support from Leaf, Prayer, Wrath. Basically everything OHKOs Sara so Prayer functionally means 33% chance to negate any enemy attack (or possibly all enemy attacks in the combat if somehow something manages to double her).
Enemy AS sucks in this game (for instance, the mounted enemies in C23 have 11-12 AS, meaning she's double some of them with wind even if she didn't level up at all in the meantime) so Sara has superior player phase offense to Homeros. In magic-heavy areas (parts of chapters 22, 23, 24, 24x, and final), she's ridiculously tanky (like 4RKOed by dark mages without levelling up at all, and like 5RKOed by the gelpritter), and can pull a wrath strategy to have superior enemy phase offense.
So, Homeros has an offense advantage against physical enemies on the enemy phase. This is a rather significant chunk of the combat, but let's see how big it is. Lategame enemies (like C16 onwards) tend to have 20-25 mt. That means the weaker enemies 3RKO him and the stronger ones 2RKO him (his hp and def do continue to increase but it takes like 13 or 14 more levelups to pull himself up to the next RKO, by which point we have 30-mt berserkers running around).
So, against weak enemies, Homeros can face two on the enemy phase. Against strong ones, he can face one. The important fact here is that when enemies come in swarms, Homeros quite simply does not have an enemy phase. In a chapter like 23, Homeros can't do anything at all on the enemy phase because the physical enemies bunch together and can't be picked off 1-2 at a time. He can still have an enemy phase against the dark mages running around, but Sara is just better than him at that.
On top of all this, Sara has A rank staves after promotion. Homeros has D. To reinforce this distinction, here's the more important staves that fall between D and A: Warp, Rescue, Rewarp, Sleep, Silence, Berserk, Restore, Reblow, and M Up. I don't think anything more needs to be said about this.
So basically Homeros has a minor availibility lead and an existing enemy phase against some enemy formations in some chapters, vs Sara having superior player phase offense and A rank staves. I think Sara wins that.
So, the comparison. This is taken in like mid-chapter 18, since Sara levels like a truck.
Homeros 10/4 (alternatively just level ~16-17, but sage promo bonuses are sexy)
29 hp, 14 mag, 15 skl, 20 spd, 7 def, 16 luk
Support from Nanna, no combat skills
Sara 10/1
15 hp, 19 mag, 19 skl, 16 spd, 3 def, 11 luk
Support from Leaf, Prayer, Wrath. Basically everything OHKOs Sara so Prayer functionally means 33% chance to negate any enemy attack (or possibly all enemy attacks in the combat if somehow something manages to double her).
Enemy AS sucks in this game (for instance, the mounted enemies in C23 have 11-12 AS, meaning she's double some of them with wind even if she didn't level up at all in the meantime) so Sara has superior player phase offense to Homeros. In magic-heavy areas (parts of chapters 22, 23, 24, 24x, and final), she's ridiculously tanky (like 4RKOed by dark mages without levelling up at all, and like 5RKOed by the gelpritter), and can pull a wrath strategy to have superior enemy phase offense.
So, Homeros has an offense advantage against physical enemies on the enemy phase. This is a rather significant chunk of the combat, but let's see how big it is. Lategame enemies (like C16 onwards) tend to have 20-25 mt. That means the weaker enemies 3RKO him and the stronger ones 2RKO him (his hp and def do continue to increase but it takes like 13 or 14 more levelups to pull himself up to the next RKO, by which point we have 30-mt berserkers running around).
So, against weak enemies, Homeros can face two on the enemy phase. Against strong ones, he can face one. The important fact here is that when enemies come in swarms, Homeros quite simply does not have an enemy phase. In a chapter like 23, Homeros can't do anything at all on the enemy phase because the physical enemies bunch together and can't be picked off 1-2 at a time. He can still have an enemy phase against the dark mages running around, but Sara is just better than him at that.
On top of all this, Sara has A rank staves after promotion. Homeros has D. To reinforce this distinction, here's the more important staves that fall between D and A: Warp, Rescue, Rewarp, Sleep, Silence, Berserk, Restore, Reblow, and M Up. I don't think anything more needs to be said about this.
So basically Homeros has a minor availibility lead and an existing enemy phase against some enemy formations in some chapters, vs Sara having superior player phase offense and A rank staves. I think Sara wins that.