Sidecars on low power bikes are fine. Especially if you like to live life in the slow lane - which I do
In the UK, you'd get sidecars on 350s, 500s and 650s in the 50's and 60s before small cars took over and killed the market. Those capacities sound "large", but a British 500 single could be a bit of a dog and a "cooking" model would defo be sub 30 bhp, with 650s getting around 40 bhp. Torgue was the thing with sidecars, more than power, which was the strength of Panthers and the like.
But in the East European countries during the cold war, it was very common to see low powered 2-strokes with sidecars. Some real beauties too. If you can manage to get a sidecar to fit an Inazuma, you will be doing well. I think that would be the major problem solved. The power output of an Inazuma is no problem. Maybe that standard low-gearing would finally make sense
Couple of pics attached.