callback order besides priority

Hello,

watcher priorities control which watcher is activated first if two
events occur simultaneously. But is there an determined order if there
are watchers with the same priority?

Example: two watchers are made to watch the same variable. A is made a
second before B, both with the same priority. If the watched variable is
modified, surely the expected events occur simultaneously! But will
there be a determined callback order as well, e.g. "A is served first
because it was made before B"?

                        Jochen