When we parse our Ninjas we count from the first move cast. The cast of Huton initiates the parse, if you are waiting the 10 - 20 secs before attacking that should be included into the number as zero DPS. That's 10-20 seconds of no dps. Otherwise you are legitimately loading the number to a very circumstantial degree. Most situations do not allow you to stand there and wait for your cool down and for all intents this should be counted against your dps. From an objective context any move that results in unsheathing your weapon should be counted as the initiation of a parse.

Another downside to going straight into TA is that you aren't capturing most of the team dps burst in the ten second window as most take a few GCDS to get to their sweet spot so you would be again falsely inflating your own dps but in this instance at the expense of your teams average.