I run a sidescan transducer and two others, the only thing I had to worry about was that the sidescan was lower than the others. One of the others goes into the Lowrance with the sidescan, and the 3rd is a redundant on a Raymarine. No issues with either, run them together all the time.
I emailed hummingbird and they gave me a vague/indecisive answer... basically that it may or may not work, being they are both hummingbird products they operate on a similar frequency. They suggested to try switching the frequencies around or to shut the sonar off of one when using the other. They said if that don't work to try moving the ducer' to the bow.