New Custom Game Mode Idea - "Jack of All Trades"

> Pre-Note: Hey, not sure if this is supposed to be under the game play discussion or feedback since I am relatively new to this, but nonetheless, just wanted to voice an idea I had for a custom game mode.

I think I would call it "Jack of All Trades", just another idea.

The Basics:

1. At the beginning of each game, a player will choose 4 champions instead of just one (Each player cannot choose the same champion another player has chosen in their 4 selection)
2. Then it will take players to another UI which will allow them to order the 4 champions that each player has selected based on the standard abilities (q,w,e,r) I think you can guess where I am going with this
3. So what this tells the game setup that while their in game, playing, when they hit one of the ability keys, the champion that they have bounded to that ability key will use that champions ability for that usual assigned key.
4. In game: the player will be either a representation of a "summoner" or some floating entity that can shape-shift into the champion who's ability you want to use right when you use it, then shape shift back into the light entity after the ability is completed.
5. The cool downs will be equivalent to whatever the cool down will be if the summoner were playing the champion in a normal game (Level of ability, items, etc.)
6. Auto attacks will all be a single base damage that will be the same for everyone regardless of runes

Example:

1. I choose the 4 champions, Lee Sin, Jhin, Teemo, and Ekko
2. Based on the selection I will be able to use Lee's (q), Jhin's (w), Teemo's (e), and Ekko's (r)
3. As you can see however I chose an ability that is sort of like a passive when upgraded (Teemo's (e)), this applies to the auto attacks of the entity essentially

Problems:

So far the large problems I can for see are the following:

1. The programming that would be needed to get this done correctly would take a lot of dedication and work
2. If there are any abilities that are bounded with a champion's passive and how that can either be broken or just applied extra in the back ground so that if there are multiple abilities tied together with passives then the summoner will just acquire all the passives tied with the selected abilities (Example: Tahm's 3 hit "acquired taste")

> TL;DR > Possible idea for a new custom game mode that could be super crazy and confusing, yet really fun. Moreover, very susceptible to glitches if not programmed and tested correctly and/or enough

So that's about it. A very preliminary and raw idea. What do you think? Something Riot can work with? Or just a far fetched idea that doesn't need any more attention than a discussion here? And, if this were a game mode, what 4 champion abilities would you pair together for a nice wombo-combo?