You just have very different approaches to most areas of the game. You want to have speedy champs, you might control other areas and you for certain want multihitters/counterattackers/ally attackers for Fireknight for example. 

In general you have many very good champions...but one team to beat them all will most likely not happen in Raid.

From your rooster I'd guess that you invested a lot in shards...but you have not played for a very long time as you do not have a Scyl yet. Watch videos on youtube for the content you are concentrating on...

General teams for campaigns and dungeons will usually only take you so far. Different content really takes different types of champs. A team that could do it all would be able to:

1) Decrease Attack and Decrease Defense

2) Cleanse debuffs

3) Heal and Revive

4) HP burn to take out both the regular and frost spiders (And a poisoner is good to have too)

5) Turn Meter control for bosses and waves

6) Inc Speed and Turn Meter boosts 

Hellhades did an example of this type of team Right Here 

Yes, but he did mention in his video hilself, that he has unrealistically good gear on his champs...therefor this might not bring the results you have been looking for

I think he took off the accessories to compensate, but I agree that it's crazy hard to get a single team going. Might be possible for farming 13s for a mid level acct though. IDK.