3 wp_query on one page with pagination for last query

At first glance, the $paged that you provide to the three argument arrays is undefined; you only define it before the third query. Either put the $args3 definition AFTER you define $paged (mind you, in this case the first two queries will still run with $paged undefined, most likely generating PHP notices in the server log), or put $paged definition BEFORE all three argument arrays.

See if that changes anything.