Summon Roles

So I want to bring up some ideas about how Summoning the other 3 Egis will work, as I believe the goal is eventually to be able to summon Leviathan, Ramuh, and Shiva as Egis as well, I also posted in the same part of the forum, a topic on wanting either to keep the option to summon Carbuncle or get a stronger version of him as a permanent summon.

Right now we have Summon 1, 2, and 3. To keep this theme, it looks like we will have a summon 4, 5, and 6... and in my case hopefully a 7. But this seems very bulky with or without the 7. I honestly wish they made Summon 1 skill that brought you to a list of Egis, Carbuncles, and Faeries you had access to Summon depending on your job, it would be much cleaner, espeically for my PS3 hotbar.

Summon 1 with Garuda is the clear leader in terms of offense. Ifrit may have more potency, but being ranged and having access to Contagion outweighs Ifrit's potential.

Summon 2 with Titan as a tank is niche... not for every situation but is good for soloing especially if you're doing FATEs in unpopular places, and thus attempt it alone or with only a few people.

Summon 3 has Ifrit trying to do cool things with his shield and stun, and it seems like a good setup, but doesn't really have any advantage over Garuda's safety.

What roles would the other 3/4 possess?

With Ramuh I want to say he'll focus more on debuffing attacks, or something that implies a more tactical concept. Ramuh is supposed to be a wise old man, so maybe his intelligence beats potent attacks and hard hits in exchange for maybe causing the next attacks to do more damage or something.

Levithan I can think of big AoE attacks with lower potency, kind of like big waves crashing around him.

Shiva I really have no clue but could possibly see her be closer to the Bard if anything, offering weaker DPS with some support effects, but I'm not sure if this would tap dance on crossing the line with Scholar.

To humor my idea of a powerful light based Carbuncle, I would love to see a counter attacker to play on the Reflect concept, shielding teammates with a buff that returns damage received. I know Ifrit tries to do this with himself but I'm thinking more of maybe a 1 time use team based reflect for a 10-20% return.

So anyone else have other ideas?