But IMO if you're seeking to specifically kill Gunboats, get a bomber.
True and True.
Although, the topic was about fighters killing gunboats, and it's easier to dodge a gunboat's turrets with a fighter, especially if the gunboat pilot is good, although, that would mean the gunboat also has the advantage of high skill, you'd have to be a pretty damn good skilled fighter to kill a gunboat like that..
un-related note: imo, Gunboats die too easily in group fights.