It sounds like you're asking the devs to implement a permanent solution to a temporary OCD issue. The number of people on earth who are actively tracking YOUR commendations:dungeons ratio is ...one. And if you would even consider not helping friends do content because of that....that's a problem. I think you should look at the (very very very) long run. Eventually you will get an achievement for running 10000 dungeons, and (if SE doesn't add one for 20000) you will never see your tracker count higher than that. Will you avoid running dungeons ever again after that achievement because it will a give false impression of how often you truly get comm'd? Or will you grin big because eventually the number of comms will grow vastly higher than 10000, and that 1 person on earth is now patting you on the back? Reality is probably neither, because you'll realize it's fruitless to even care about the issue.
As an easy 'fix' maybe go pug some nice 8 man content, and be such a stellar person that you start walking away with 3 comms per duty. That should create a nice ratio buffer to allow you to help your friends with a clean conscience.
I have 2932 comms and 3354 instances run, AM I A TERRIBLE PLAYER BECAUSE MY COMMS ARE < DUTIES? If you had the insider knowledge that I have a static for raiding and Ex trials, and ran literally HUNDREDS of 4 man duties solo/unsynced to light farm 9 Novus relics, what would you think of me then? I must run most content as a tank or a healer? I'm talkative and sociable? I do tons of 8 man pugs? I just got lucky and played with people who aren't stingy with their comms? Nothing really, each one is just an independent tracker for an achievement. And when achievements are gotten, the rest is.
TL : DR If the devs implemented something for this, it would be setting a precedent for a LARGE number of future fixes for personal problems players have, and take away from real development for larger fractions of the player base. The solution lies with you.