Why do enlisted stop at E-9, but Officers keep going O-5-O11

Actually the Senior Enlisted of each service does receive special pay for their position.  The SMA base pay is over $7,700, nearly $300 more than a CSM with 40 years (Which no CSM has because their RCP is 32 years unless they have been nominated to serve with a General Officer). The officer pay scale only goes to O-10 (4-star). I do agree that each service should be authorized one E-10, the SMA.

As for comparing our system to the British, you may be a little off. The British have less enlisted pay grades and they promote much slower than we do. Also, their OR-8/9 (NATO Rank meaning "Other ranks") are considered Warrant Officers and have surpasses the NCO ranks.

What do you think creating different Sergeant Major ranks would accomplish? There duties would still be the same, they would advise the commander. When an officer achieves the rank of General (which less than 1% of the officer corps achieves, and officers only make up 13% of the total force, from O-1 thru O-10) they have huge levels of responsibility. Their influence on an organization is far reaching. Since a CSM is an adviser what would be the purpose of having a higher rank? A LTC can't be a BDE commander and be the Senior Commander to other LTC who are Battalion Commanders. Even though CSMs exert tremendous influence they are not the raters of their subordinate CSMs. I think the NCO sometimes forgets that. It is frustrating to see a company 1SG running around doing what the BN CSM is telling him/her to do, yet he/she is rated by the Company Commander and Senior Rated by the BN Commander?

Would you recommend a change in duties? Should the scope of their duties be expanded.