It should work good. I have a hummingbird helix on the front plugged into my motorguide xi3 and it’s just as good as the factory. Just note 2 things.

1- your garmin will only do what your terrova transducer is capable of like side imaging and downscan may not work if that transducer won’t do it.

2- make sure you get the correct cable so you can plug your garmin into your terrova transducer lead.
I would also talk to someone from garmin to make sure your imaging will work with the trolling motor transducer. My transducer doesn’t have imaging so I just bought a basic helix. The extra stuff wouldn’t work and would be a waste of extra money. It is very convenient because you can’t just tie your garmin transducer Cable to your terrova shaft because it’s motor driven and the cable will twist around it. You have rig it off the shaft.