Chandrasekar Natarajan, a PFE based in Canada, runs through some example PowerShell scripts for configuring SharePoint 2013 Search Service applications and topology configuration:
Each Search service application has its own search topology. If you create more than one Search service application in a farm, it’s recommended to allocate dedicated servers for the search topology of each Search service application.
In this blog, we will see how to configure topology for one search service application with multiple search components across 2 servers for redundancy and performance.
Lots of scripts and lots of detail; scripting this type of operation can save you time in the long run. (Or can it? You do the maths!)
Posted by Tristan Kington, MSPFE Editor and recent barbequeue purchaser