It's up to you whether you want rapid heal or area heal. I personally went with area heal because Saria gets +15 range as her AW passive. Might seem lackluster for an AW passive, but it does help units like Saria reach out to more units. Plus, if you couple her with Rinne (black feng shui user), you get the perfect healing team. Fast area heal from Saria and multi-heal plus 50% physical evasion from Rinne. Furthermore, Saria gets even more range after 2nd AW. I kinda made a showcase of Rinne's insane range increase during skill in my new Spirit Rescue G vid: https://www.youtube.com/watch?v=HIsn5TbmxKo.
I only have Rino and she can only deal magic damage compared to Solano and Farne's true damage. Her unlimited skill duration after S.AW makes up for it though.
Dolce, while nice to have, is for missions with a ton of demons. Monster hunters usually have some ATK up for the type of mobs they go against. Demons for Dolce, orcs for Rosel, and dragons for the sapphire one (forgot her name). Out of those three, Dolce will be the one most used because 1) she is a gacha unit and 2) the majority of the missions feature demons. Rosel excels in the jungle maps because it is the home of the orcs.
Btw, we're getting a new priest warrior in the next event and Elva's revival so that's more SC for ya.