I agree with you that is wasn't easy for City to win UCL even with their strong performance. City have only won it once and this happened when they were in their peak form because if you look at it, they have won EPL four consecutive times but within that period they have only won UCL once.
Arsenal is not as strong as City and that is why they should focus more on winning EPL first, if they have won EPL twice maybe that will strengthen and improve their mentality to focus on being champions because they have already tasted winning a title, I think that will motivate them.
You have some points in what you’ve said about Arsenal and Manchester City but that is not entirely the way it would always be. You don’t have to be a champions in your domestic league before you can be champion in the champions league. I know that the champions league is more intense than the premier league and all teams needs to put in their best effort before they can even dream of winning the champions league. But if they can be able to to put in their best effort into just one competition, they can come out victorious. Like focusing just on the champions league without giving much effort to the domestic can make them win the league ahead of others. They just need to use the right players and apply the right technique to make it easier for them to prevail.
@Asiska02 I read everything he said and if you ask me, I don't he meant to say that Arsenal must win the English Premier League title before they can win the UEFA Champions League competition but that Arsenal is not strong enough at the moment to win the UEFA Champions League at the moment so they should rather focus more in the English Premier League which I think is a good idea. Arsenal manager Mikel Arteta has really done well to improve the team but still have more work to do before they can be considered a strong contender for the UEFA Champions League.
I think Arsenal can win the English Premier League title with the current squad if they can be as consistent as they were in the last two seasons but they have to make few signings this summer to improve their chances of winning the league title that's eluded them since 2004