I suggested a few names couple of weeks back.
Here's just a few
Maxwell
Baines (the obvious choice, please Levy)
Bastos (top player)
Taiwo (hard to persuade)
Perrreira
Coentrao (most likely impossible)
Didn't say Santos is the solution - attempt to read / comprehend before deciding what I've written
It's BAE's fault for X, for X, for X, for X. His covering of King's ass was not good enough... What sort of insanity is that? It's BAE's fault because he has too many vowels in his name... There, I made it easier for you.
Andre Santos, the Arsenal LB cannot defend. RVP can defend better than him. (Proof I'm not just saying it because he's an Arsenal player.) He is more like a winger than a left back, he is one of the worst LBs in the entire league. It is insane to claim Andre Santos is better than any remotely decent LB. I honestly would feel safer with Rose.
Santos is best going forward but VDV would put in a better attempt at playing LB... Santos doesn't track back, he never plays without someone's shirt in his hand, he is the liability of all liabilities. With the exception of the CL game he got injured in, I've watched all his games. He's taller than Defoe, but even Defoe isn't as brick at defending as Santos.
Enrique turned to brick lately, but was one of the best LBs in the league... Evra started off badly but has picked up. Cole started brick but wasn't helped by the lack of help in front of him. He had to do a Walker and mark 2 men for a few games, but he's a good LB. It's an incredible insult to say any top 6 starter is worse than Andre Santos... In fairness to you, Wenger prefers Gibbs, even though he plays one game and gets injured for a month. BAE is better than Gibbs, but at least Gibbs has some right to play as a left back.
Ok, so now to your actual list...
Maxwell - Is this the Maxwell that used to play for Barca? I don't know him well enough to judge honestly, but the few times I saw him, he didn't seem like an OMGWTFBBQ LB.
Baines (the obvious choice, please Levy) He has been really bad defensively this season most of the time when I've seen him. But he can take penalties, free kicks and can cross well, he's great going forward. He was better defensively
Bastos (top player) I don't know him well enough.
Taiwo (hard to persuade) I don't know him well enough either.
Perrreira I don't even know this guy.
Coentrao (most likely impossible) This is the Real Madrid LB for away matches? The better defensively out of him and Marcelo.
I agree that Baines is the obvious choice, before this season began, I actually half expected that to happen. But because of that I've looked at them both and I think Baines this season would have got a lot of flak from people here if he'd put those performances in for us. He has hard workers in front of him that track back, Harry likes leaving Bale up to counter with.
Coentrao is the only one I know well enough to judge other than Baines and Coentrao is an amazing LB, but he plays for Real Madrid. If we could replace our entire squad with Real Madrid players (even ones that only play half of games for Real Madrid), we'd be challenging for the title.
I haven't totally condemned your list or anything, so I'm not saying BAE is the best LB ever, because I know some people love him and some hate him. (Not just due to his personality, Arsenal Mania is divided, some think he's the best LB in the top 5/6 and some think he's the worst.)
I just strongly disagree with the Andre Santos comment. BAE would get into the Arsenal team for sure. Man United, Chelsea and even Liverpool have good/great LBs (if you consider previous seasons especially), but Andre Santos would struggle to get into any other team in the PL. The ones at the bottom of the league need full backs that can defend. He'd probably get in as a winger.