Walcott will give us more than Lookman like (at the moment), he needs a season playing every week somewhere.
I know it's a bit of a basic way of thinking but I just don't see the point in signing players that aren't good enough for the top six in order to try and get there ourselves.
That's where you meet the reality of building a team. Too many of us have an expectation that we should only buy the absolute 'elite' players and that is impossible to achieve for all sorts of reasons. But if one keeps improving then one's recruitment improves as well until you reach the point where the 'Messi's' of this world start to find us an attractive proposition.
I agree with mikey_blue there will certainly be more 'Walcotts' to come before we start seeing the 'Agueros'.
The frustrating part of watching us at the moment is the impatience many of us have. We talk ourselves down too much. Overall our situation is improving - if you don't think so look at the teams outside the top 5 and ask 'are they on the way to the top?' I can't see it. Leicester did it for one season and that fluke event does give other teams hope, but season after season at the top? I don't think so.
There is a lot of pleasure and satisfaction in watching a good team develop but we seem to have lost that in favour of wanting and expecting we can have it all now, now, now.
Life isn't like that.