I have had Security+CE since 2011 and N+, A+ since the late 90's. It is a pain in the butt to keep renewing the Security+ but it is required for DOD contracts.
I did like renewing the Security+CE to renew the A+ and N+. It takes care of all the stupid alphabet letters that want to see which keeps me working. 

The below pyramid shows Linux+ as being a "higher cert" than "Security+". However, it looks like it only renews the A+ Cert. 
https://www.comptia.org/continuing-education/learn/renewing-multiple-certificationsIt seems that Comptia's statement of "
Renewing higher-level CompTIA certifications can fully renew your lower-level certifications." is contradicted if I am reading things correctly.I would have liked to take the CASP first as I mentioned in a previous post but ended up with an emergency need to take the Linux+ to keep the bean counters happy. 
I am due to take my Security+ in about 1.5 years to renew it and the N+, and A+. Does this mean that every 1.5 years I will either be renewing my Security+ via Certmaster CE and my Linux+ via??
I am confused and don't want to create more work and stress for myself and have to dish out too much money.
Thanks.