if it was ME , I would get a Bunch of those up to 50 for Faction Teams to Farm Glyphs ,,,

and the Free Bonus Books etc from the Faction Dungeon stars

But what do i know ...

60s > 50s

Please don't make a bunch of 50s early game just for FW lmao

To start, I'd get Cardinal, Fayne, and Zargala to 60 before Psylar. Cardinal and Zargala accelerates your dungeon progression, and Fayne helps your CB damage. 

I would make ZERO decisions based on FW progress until you are at end-game or very late-game.  After 15ish months I am just getting to the point where FW factors into my decision process

Cardinal and Zargala to 6*60.

Contrary to other people I won't tell you not to even think about FW. That's what makes this grindy, boring game worthwhile for me at all, because team composition is fun; all the rest is dull, and "efficiency" is pretty much the last thing for which I play any games. But I actually think both those two are superb champions and will be useful in many situations. Cardinal is such a superior reviver, and revivers allow you to farm anything beyond your regular capabilities. And Zargala slays -- I don't have her, but I sure would like to.

Sandslahed  is  also  a  great  champ  and  you  have  2!  great  for  Cb  and  progresion.

amazing  passive 

Getting a "solid" team for FW to farm 3-5* glyphs and epic/legendary material doesn't seem like a mistake though. For example, Perception set is very good and cheap to craft. The better glyphs will massively increase your best champions' effectiveness. For example, if you got +4 speed glyph rolls instead of +2 on five artifacts, you'd have 10 more speed right off the bat. The same argument could be made about any substat that can be upgraded.

Getting a champion to 6* is roughly the same amount of work as getting five champions to 5*. Having additional 5* champions will be the reason you can farm more/better glyphs and material from all the factions. However, if getting a champion to 6* would enable you to farm a dungeon on stage 13 on auto which you previously couldn't do, then getting 6* is arguably better.

If you can confidently farm all dungeons but spider on stage 13 (I guess you can't), then you probably aren't in the biggest rush to 6* star anybody right now. It depends on whether you want more clan boss damage, go deeper in dungeons, manage to farm spider 10+ on auto, etc. That's how I would make my decision.

It doesn't seem like you got a lot of support champions that can keep your allies alive. I myself am rather new to the game and thus don't know all the champions you got, but maybe focussing on Rearguard Sergeant could help? Even going for Mistress of Hymns could be helpful in your situation, if you need a reviver. She isn't great by any means, but maybe she is what you need. It definitely looks like your current team won't survive a lot of damage.

What you can also do is to save your food and wait for a better champion to drop that suits your needs, but that's not really the most entertaining way to play the game and will only tempt you to spend money on shards.

I think Cardinal, Zargala and psylar (note I have neither) will help your progression most.  Sandlashed is great and leveling up her is wise as well, unfortunately your current roster does not synergize well with her (extending your buffs).