When should I use SMN’s diffrent Egi’s?

Was thinking of posting this to DPS roles but this fits better here imo.

I’m about to unlock SMN today or tomorrow but I’m not sure what I’m gonna use Egi’s for. I’ve mostly used the Emerald Carbuncle in POTD and sometimes the Topaz one when I need shields in case something goes wrong, but what about the Ruby Carbuncle aka Ifrit for? Single targets?

What am I gonna use Titan for? My personal tank for FATES, POTD, H-O-H etc? But wasn’t titans ability to tank removed? And what about Garuda? Groups?

Ifrit for single target, Garuda for aoe and Titan for it youre solo and for some reason think youre gonna die

I switch between Gardua and Ifrit regularly in dungeons. Garuda on trash since it's very AoE centric and Ifrit on bosses since it's very single target oriented. If I'm feeling especially plucky I'll even switch to Ifrit if there's a single mob left at the end of a pack, but most of the time I don't bother in that case, since even though the summon is instant you'll lose a couple of the pet autoattacks while the pet gets it together. A good mid-fight example of a switch would be

the cocaktrice boss in Amaurot. Start the fight with Ifrit and switch to Garuda when the add phases start and then back to Ifrit for the last dps burn.

As for Titan, it is useful when out in the field to give you a bit of a defensive boost. Most of the time I go for Ifrit in the field, however, since it does more damage and won't accidently pull adds with AoE. I never use Garuda in the field for that reason, unless doing FATEs and am very confident that a tank player is grabbing all the fate mobs for me.