Macrosociology and microsociology seem to make very different assumptions about how society works. how does sociology, as a discipline, deal with these two very different perspectives?

Macrosociology ficuses on the large scale social processes, while Microsociology focuses on the small-scale, individual or small group interactions.
Macrosociologists  use a combination of historical and archival research, and analysis of statistics that span lengthy time periods in order to construct data sets to analyze the social system in general.
Microsociologists, on the other hand use research methods that involve direct interaction with research participants,ethnographic observation, focus groups, as well as smaller-scale statistical. 
The sociology as a discipline deals with these two very different perspectives such that it combines the research methods, assumptions, and the benefits from disciplines to gain better and better results.