Confusing subject perhaps, but hard to describe in one line

I have Chromium browser installed, and it is my default browser. I have it locked to the Launcher in Unity. What I am seeing is, that if I am running Thunderbird email, and Chromium isn't running, then I click on a link in an email in Thunderbird, it opens Chromium browser, as expected - but, instead of it showing in Launcher as an indicator alongside the existing Chromium icon, a second icon appears lower down. Just saying it would be better, and neater, if it realised the Launcher already contained the app, and just indicated it was running by adding an indicator, instead of filling the Launcher up with extra icons.

It is also annoying, if you are used to clicking on an app icon to switch to it, especially when it is on a different workspace, because you invariably click on the one not yet running, and it launches a new instance of it instead of switching.