The first problem that you will have is trying to use the LOR contollers in their native mode. Your best bet would be to use them in DMX mode. In the past if people wanted to use native LOR commands, they would sequence in LOR software and use an IDMX unit like you have to control their DMX units. The problem now is that you have pixelnet in the mix and the IDMX controller does not support that and the smartstring hub does not support LOR native commands. Fortunantly, the smartstring hub supports pixelnet and DMX and the LOR controllers can also work with DMX which is why I suggested using the LOR controllers in DMX mode.
As for the strings that you can run, you really can't look at it that way because after all, what exactly is a string? A string can be any length from 1 to 128 nodes and can be configured in one of three modes which affect the numbr of channels required. In pixel mode, every pixel that makes up the string uses 3 channels while in string mode, the entire string regardless of the number of pixels only uses 3 channels. In hybrid mode, each string uses 3 channels per pixel plus 3 more for string control. If you decide to have the hub output DMX, then just subtract 512 from the 4096 channel pixelnet universe and you have 3484 pixelnet channels available. Then just determine how you intend to configure the strings and do the math to determine how many strings you can run on that universe.