Creating and Editing objects in a list based on user inputs

Howdy!

New to appgyver and looking to write an app to solve a daily workflow.

Use Case: Esports tournaments perform pick/ban processes where two teams go back and forth selecting which maps are banned from the map pool, who will host the map, etc. Currently many of these processes are on paper - I am trying to turn it into a simple app to remove some of the inherent mistakes that currently happen.

Page 1 will collect basic information from user inputs based on lists.
Dropdown 1 - Official Name (who is officiating the pick/ban process from a set list of known officials).
Dropdown 2 - Higher Seeded Team (Offical selects which team has the higher seed - decides actions on coin flip next page - from a set list of known teams).
Dropdown 3 - Lower Seeded Team (Offical selects name of second team who is lower seed - from a list of known teams)
I have this page pretty much figured out - and have the lists populating, and then use the “selected value” option to store the results in an app variable (officalname, higherseededteam, lowerseededteam). Submit button then takes the user to the next page for a “coin flip” to occur.

Page 2:
V2 of app will include a automated coinflip integration - but for now the page has the following fields:
Dropdown 4 - Coin Toss Winner (Official selects name of the team who won the coin toss). This is where my first problem comes - I want to use a list in this dropdown that is made up of the values of app variables higherseededteam and lowerseededteam, but I cant figure out how in the world to populate a list with these values. I have tried formulas, etc - but I think my syntax is wrong. What would the best formula be to generate a list from these two app variables?

My next problem that I know I am going to run into is the map pool selection process.
Team 1 will have a set of say 5 maps, and ban one. Then team 2 will ban one. Then Team 1 will pick the first map to play, team 2 the second map etc. How in the world do I take a list, and then update it to remove the option selected by the first ban/map pick, etc?

Thanks in advance for any help! If anyone happened to want to do a discord session and knock this out with me, I would be super grateful! I really just need help understanding these two problems, and then feel I can “replicate” them through the entire process just fine.

Alex