You want to bucket leads into two or more groups and deliver them according to various endpoints depending on what bucket the lead ends up in. This is a common workaround in LeadConduit for Round Robin and A/B split testing scenarios.
LeadConduit appends a randomly generated number between 1 and 100 to every lead. This random number can be used for a variety of use cases, including this one.
Here you can make use of the Random Number to set Step Criteria on your various delivery steps to bucket the leads based on ranges of the randomly generated number.
For example, for a 50/50 split, you could set the Step Criteria of the two deliveries as Less Than or Equal To 50 and Greater than 50.
NOTE This approach isn't a strict 50/50 binary split, as it is possible for any number of leads to be delivered to the first delivery endpoint in succession before a delivery to the second endpoint. However, you'll find over a given timeframe with enough lead volume, deliveries will even out very close to a 50/50 split, and for many clients, this is sufficient for their needs.