To add to Chip's comments, I think you need to think about why you are blending and what you are trying to achieve.
Often, blending is used because Dialer is being used to generate additional work when there is excess capacity on an inbound queue. i.e. you have scheduled more agents (for whatever reason) than are actually required to service the inbound workload. This is what the "Inbound Queue" settings on a Campaign are for (ACD Tab) - they allow the Campaign to monitor the inbound workload and stop dialing if there's enough work to keep everyone busy.
Of course, if you need the outbound calls to happen, you either have some Agents dedicated to Outbound, or deliberately over-staff based on your expected volume. In the latter case, would still set the monitoring of the queues up, though, since that will allow for unexpected "blips" in the inbound workload.
HTH