I can compare pretty much like for like. I had a Bayliner 2655 (Hardboat
). When it was new I added a 5hp Mariner longshaft. The engine sat on the transom for years without ever having to use it. On one rainy and boring day on the broads I decided to give the auxiliary a try.
It was useless ! At full power the boat began to move forward after around 30 seconds, top speed was less than 1 knot. Reverse didnt work at all. it just couldnt get a 'grip' on the water and no where near enough grunt. Against wind or tide the boat wouldnt have moved, I think with your much deeper V hull you would be lucky to get any movement at all.
I swapped it for an 8hp extra longshaft saildrive Mercury. worked a lot better. Forward and slowly reating reverse, would do 5-6kts at WOT.Downside was weight, it was over twice as heavy as the Mariner and it required a whole new bracket the fabricated.