Much of the viability of the liquid yeast depends upon the date of packaging and storage conditions before use. Most likely, you are perfectly fine in your pitching rate.
BTW, the nutrient package in the Wyeast yeast smack packs is there to 'proof' the yeast and does not contribute much to the viability or yeast count in the pack. If it does not break, it is really not a bit deal.
One of the ways I use the liquid yeasts in my 10 liter batches is to make a yeast starter, oversized to the amount that I need to pitch. I then split the starter for my batch and store the rest in my beer fridge for the next batch. It works well if you are doing several batches in a row which you are calling for the same strain of yeast. The typical starter will last 3 to 4 weeks in the fridge without issue.