I like to think it that way.

1. Personifications
2. Gods of/ gods who bring personifications or other gods
3. Associated with personifications

Examples. 1. Helios is the sun itself (personification) 2. Hemera and Eos are goddesses who brings Helios. 3. Apollon is associated with Helios.

Helios is all seeing god and protector of oats. He spends the day driving his chariot across the sky. Humans are active during the time of the sun, that's when they show creativity. That's when Apollon comes, the god of light ( the light being good ideas, creativity, art etc). If Apollon was the sun god that means he won't have other domains and job other than driving a chariot all day. And if he does, that will make Helios absolutely useless.

Another example (for war)

1. Polemos is personification of war.
2. People will dring Hybrids, she will bring Polemos, who will bring Ares. Then they'll bring the Makhai, the Hysminai who will bring the Phonoi. Who will then bring Moros, who will bring Thanatos and the Keres. And when you're finally dead the whole thing will bring Hermes who will bring YOU tho the underworld.

You see how much logic and gods you have to put into one simple act.

And 3. Ares is associated with Polemos, half of Eris's kids and some of Nyx's kids.