View source for Talk:Empire/Ranks/@comment-74.215.211.11-20180313020830/@comment-98.175.48.62-20180314003756

The servers are not bogged down. Even when your rank shows 100% you're still building rank towards the next rank up. The Naval Progression missions are more of a uncommon spawn, it'll take several missions here and there to pop one of them up. Make sure to also get you Empire Relationship (also known as Super Power Relationship) to friendly, that will increase the spawn rate of those missions. 

P.S They don't stack with rank (you can't get two as a duke, and complete both to get to Prince and King.