Merging forms with different structure is very complex area, and really out of the scope of the functionality provided by ConfiForms TableViewMerger, but here is what could be done...
Data in form f1
Data in form f2
Merging together
Merged column is configured like this Merged:(ZEROIFEMPTY("[entry.myfield2]") + ZEROIFEMPTY("[entry.myfield1]")) |