Holloway was getting the better of Poirier in his UFC debut that he took on short notice and it is clear that his technique is superior (Holloway, that is). Siver is more varied and likely a better striker than Poirier as well as I see no reason to put him below DP on said list (from a technique standpoint).
Conor is a poor matchup for both of the individuals in question. Diaz has shown weakness (severe) against an individual that does a lesser version of what Conor offers and Cowboy struggles against boxing-oriented talent (as a result of his poor headmovement and slow-startup).
No he wasn't getting the better of Poirier on the feet on his debut, it was pretty even and the knee that Holloway threw right before Poirier went for a takedown missed and Poirier landed a punch or two when they disengaged, the only other significant thing was that they traded some leg kicks. Siver got his ass handed to him by Cub while Poirier went the distance.
Regarding the matchup with Diaz what the fuck does a lesser version mean and how does that apply in the LW division? And Conor hasn't fought such an aggressive striker who is bigger and virtually as long as him with Cowboy, also someone who is better than Poirier on the standup.