Gracie2012

The muskolosketal ratings are here: 
 
https://www.law.cornell.edu/cfr/text/38/4.56
https://ecfr.io/Title-38/Section-4.45
 
https://cck-law.com/blog/va-disability-for-ankle-tendonitis/
 

You’ll have to look up your tendinitis decision to see what they considered. Most likely it’s already covered under tendonitis but we don’t know that - you have the decision letter. If it’s on the same mri then it’s probably already been considered. 

The max rotator cuff for major is like 30 percent. The VA connected my left Minor at 20 percent just a month or so ago. Read the regs and range of motion carefully.   

Only you know whether you think this was a lowball, and it sounds like you were denied others.  
However, besides denials and delays, lowball is a favorite of VA.  
If you think you deserve higher, then appeal.  It sounds like you do, or you would not have asked if you were content with your rating.  
Remember, you can appeal 3 things for every issue:
1.  You can appeal any denials.  
2.  You can appeal the disability percentage, if you think it should be higher.  
3.  Last, but not least, you can appeal the effective date(s).  
      My advice:   You can get your records amended, if you feel some or all are in error with this regulation:  
     https://www.law.cornell.edu/cfr/text/38/1.579
     Of course, if VA refuses to correct those records (maybe not), you can appeal that, also.  
     I would advise appealing pretty much everything.  Remember, 38 CFR 3.156 C, means you should get the effective date the day after exit from service "provided that" you applied with a year of exit from service and vA had not considered evidence, but then found records, such as if you resubmitted them.
     38 CFR 3.156: https://www.law.cornell.edu/cfr/text/38/3.156