With Elliott, he might be playing well, but you have to think, he is a striker, his primary role is to score goals, so ask yourself, do you think he can score the goals? I'm sceptical in all honesty. Clarke can function as a lone striker, he and the team need to adapt to one another. Look at some of the best teams in Europe, they play a lone striker and most of them are big lads e.g. Ba, Gomez, Ibrahimovic, and some others, it can work, just needs time. 4-4-2 hasn't worked particularly worked for us and 4-4-1-1/4-5-1 has worked, sense alone would tell you not to play 4-4-2.
I'm a vocal opponent of 4-4-2 (on this forum, I don't go out protesting!
), I have given reasons (and facts) why we shouldn't play it, and no one has really put forward a compelling case why we should play 4-4-2 tbh.