Yes, you can. Coupler.io enables you to add multiple sources when setting up the importer. It's also possible to combine data from these sources before importing it to Google Sheets.
Do this in the following ways:
Union: Add data elements from one of the added sources to another. To merge data, ensure columns in both sources are named equally.
Join: Combine two data sources side by side. One column in each data set must be the same.