People watch the Mendes fight and go "See! That's how you do it!" completely ignoring three facts:
1) That is Chad Mendes who has one of the best shots P4P in the UFC
2) Chad had to get lit up in standing exchanged in order to land the take downs he did.
3) Conor still stuffed 3 of 7 attempts by Chad and had yet to be taken down by anyone else. That's 7 attempts in 2 rounds from one of the best in the sport. That's over 17 times in a 5 round fight. Few fighters have that kind of gas tank.
Yes, there seems to be a path to victory here if you take a Chad Mendes, give him better defensive striking skills and a lethal BJJ game...but there are very, very few fighters that fit that mold.
Take Alvarez, for example. Conor would have murdered him if McGregor was in there instead of Pettis. If Eddie thinks that performance he put in against Pettis is how you beat McGregor he is insane.
RDA has some parts of the puzzle to beat McGregor, IMO, most notably the BJJ if he get's him down. I don't think he has the striking defense or wrestling to round out the rest. As a Conor fan I want to see RDA get him down. I want to see McGregor grapple against a dangerous black belt. I just don't think RDA can force the fight to that position.