But at the cost of one capital ship. Taking the rebel cruiser out with regular weapons is much more cost effective.
If Lucas had gone for that option at the start of ANH, the film would be very long indeed.
I don’t follow what you mean by this? Wasn’t the beginning of ANH basically a sublight chase?
Yes, where the bigger ship quickly caught up with the smaller one. It wasn’t stretched out across an entire film to serve as the rather weak (imo of course) backbone of the rest of the movie.