When responses are merged and copied to another survey, they are counted as additional completes for both survey and account. For instance, if there are 100 responses in one survey and 100 responses in another, the total count will be displayed as 200.
To Summarize this further - When you Merge data from survey A into survey B, survey B will include additional responses from survey A. Consequently, the total number of completed responses for that survey as well as account will increase. Therefore, yes, each license"s completed counter will be affected.
Deleting data or responses will not change this counter.