Disclaimer. I haven't participated in clash ever.
1) Allow players too create teams with which too participate in clash matches.
- ideally with more than 5 players in the team, i.e. subs (since, it's not expectable for everyone too be available at same time all the time.)
- this makes organising and timing easier for the teams, and resolves many of the timing problems/excuses
- 'if one of your players cant make the time, just use a sub'
-- at higher levels, players will usually have the time due too competitive drive
-- at more casual levels, the sub system resolves conflicts easily
2) Calculate & setup challenges between teams of a similar mmr regularly (possible show a list of teams at a time) - however, require them too be accepted by both teams, with a given (changable) start time.
- optional, also allow teams too challenge other teams through challenge requests casually
3) Have a progression system, and also a blocking system.
- Once, you reach a certain 'rank', you must accept a set number of challenges setup by the system, and must play the match out within a set time period, or your team will drop scores/rank.
-- constraints increasing, higher you go which is fine, as teams will be more competitive and desire better and more serious competition anyway
4) After a team is shown too be reliable and has displayed a base level of punctuality, allow them too enter more events.
5) Have tournament periods (casual/comepetitive), where you pool together teams of a similar rank, and have them 'clash' it out.
- casual tournaments of only a few teams, that don't take much time and is mainly for fun
- competitive tournaments with more rigid rules, but is more organised and strict, but has better rewards
6) Very serious teams, possibly can be put in leagues, where similar level teams play each other x2 over a period - with a well defined start time each game.