Baines is a far bigger threat going forward than either of those players, IMO. The only thing they probably have on him is pace.
I usually agree with your opinions but there is no way Baines is a bigger threat going forward than Coentrão. Coentrão was actually a winger at Rio Ave and early stages of his Benfica career. A very attacking one, with a decent repertoire of dribbles and ability to go past opponents with pace and skill. Then Jorge Jesus converted him into a left back in a an attacking minded setup where the full backs were crucial in the offensive manouvers. The result was that he became the best left back in the league, an essencial member of our national team (best left back in the last 30 years) and earned a Real Madrid transfer. His influence in our national team in what concerns our attacking threat (even though he is a left back) is only second to Ronaldo and Nani. Baines is better at set pieces and crossing but Coentrão is also a very decent crosser.