I expect to see Pochettino help Chelsea to be on top of the table but that's not going to be easy for them in their current situation that's why we should wait and see how Pochettino is going to rebuild this team because the Chelsea we see right now is completely broken and this will take some time for Pochettino to do some reworks with his team and make them have better performance than we saw in the last season.
I think it is unrealistic for Pochettino to help Chelsea get to the top of the league with just 2 months into the new job; new players and new signings too. Pochettino has alot of tasks and work to put Chelsea in place; determine a starting 11, develop the team rhythm and chemistry before even thinking about a title challenge.
Worst case scenario, i think Pochettino should be able to get Chelsea to fight for an Europa league position because even Champions league football is far fetched (atleast on paper).
Many tasks await Pochettino since starting his new adventure with Chelsea, he needs to build a solid squad with good chemistry between his fellow players. Building a team full of newly-arrived players is not an easy job for Pochettino, he has to do a number of experiments in formations to determine which players are still in the core squad.
Pochettino can use the pre-season to test how strong his team is, he needs to find the right formation to bring Chelsea to the top four.