So there would be 4 English teams in that case? If so then why were there 5 Spanish teams in it this year if the same thing happened (Spanish teams winning CL and EL)!?
Possible Scenarios, with only 4th spot altering and both Liverpool and City winning their European competitions:
1. Leicester City - Qualify for Champions League on league position.
2. Tottenham - Qualify for Champions League on league position.
3. Arsenal - Qualify for Champions League on league position. If City win the Champions league they will enter the playoffs. (I think)
4. Man City - Qualify for Champions League on league position or winning it. Winning the Champions League would automatically put them in the group stages
5. Man Utd
6. West Ham
7. Liverpool - Qualify for the Champions League by winning the Europa League. Could be 1st seed if one of the top 7 leagues champions wins the Champions League as well.
etc...
1. Leicester City - Qualify for Champions League on league position.
2. Tottenham - Qualify for Champions League on league position.
3. Arsenal - Qualify for Champions League on league position. (Again would probably have to play the playoff round).
4. Man Utd - Drop into the Europa League.
5. Man City - Qualify for Champions League through winning it.
6. West Ham
7. Liverpool - Qualify for the Champions League through winning the Europa League.
etc...
So in summary 4th would drop into the Europa League if a 2 teams outside of the top 4 win the Champions League and the Europa League.
Last year Spain had 5 and none of the top 4 were affected because the winners of the Champions League were already in the top 4 (Barcelona).
Also the scenario below is why we may cheer on Liverpool if we have a chance of winning the Champions League:
1. Leicester City - Qualify for Champions League on league position.
2. Tottenham - Qualify for Champions League on league position.
3. Arsenal - Qualify for Champions League on league position.
4. Man Utd - Qualify for Champions League on league position.
5. Man City - Qualify for Champions League through winning it.
6. West Ham
7. Liverpool
etc...
Also the nightmare scenario:
1. Leicester City - Qualify for Champions League on league position.
2. Tottenham - Qualify for Champions League on league position.
3. Arsenal - Qualify for Champions League on league position.
4. Man Utd - Qualify for Champions League on league position.
5. Man City
6. West Ham
7. Liverpool - Qualify for the Champions League through winning the Europa League.
etc...