No he is not right, as engines designed for or converted specifically for RC flying are usually more refined and generally more powerful than commercial trimmer or similar type engines. Don't forget that the majority of RC engines started out as either chainsaw or trimmer engines before being turned into our little jewels.

HP values for an RC engine can be misleading, as an engine can develop it's max hp at so high an rpm and with such a small prop that makes it not practical for RC use, while a max torque reading with it's associated rpm is of much greater value, as it can be used to assist in determining what size prop will give the best performance from your engine.

Karol