Merge Replication identity field issues
You could turn off automatic identity management and allocate your ranges manually. 
Another option could be forcing a range re-allocation by issuing sp_msrefresh_publisher_idrange and specifying the range boundaries.

However, both options would not guarantee that the lTID column is populated with ever-increasing values: you will always have at least one range for the publisher and one range for the subscriber and if users are inserting at both sites you can't have ever-increasing IDs. 

This is by design and there's no way around it.

If your goal is keeping the identity values generated at the subscribers ever-increasing, that's a whole different story and it can be achieved with one of the above options.