Based on what? Garrison and Hamhuis were out for one lucky goal against out there today in that 1st period. Edler played with Bieksa and that was horrible. Tanev with Alberts the same. Bieksa was on the ice for 3GA, he should be sheltered right now rather than shutting guys down with Hamhuis.
Ballard - Tanev is a whatever pairing. They can mop up the super easy minutes but that's a misuse of Tanev's talents while putting the other 4 guys in an unnecessarily tough position. They also don't generate any offense despite playing those easy minutes which is a major downside.
If you can move Tanev into Top 4 and use Bieksa to generate offense ala Ehrhoff in 09-10 then you do it.
It's about getting the most out of the unit as a whole.
Hamhuis-Garrison has been okay, yes. But we've seen time and again that Bieksa is a trainwreck without the right partner. And he's absolutely nothing like Ehrhoff in terms of generating offense like that. If you put Bieksa out there and ask him to play an 'offensive role like Ehrhoff' he's going to go off the rails completely defensively, and he just doesn't have the natural offensive/puck moving gifts that a guy like Ehrhoff does.
Edler-Tanev has looked okay-ish as well, but it's asking a lot of Tanev at this point to play those minutes every night, and even with Tanev, Edler has still been largely a mess and Tanev has started to show signs of struggling a bit when burdened with that load. Why not use our $4.6M 'defensive rock' and veteran that we splurged on in the offseason to play the role?
Alternatively, you put people with the players they've shown chemistry with, find out if your '2nd pairing' guys can play together...and if they can, you get 1)a top pairing with HamJuice that has shown great chemistry and when clicking, is easily superior to Hamhuis-Garrison. 2)a way of getting Edler to look like a $5M defenceman and maximize the value we get out of our 'steadying influence' acquisition. 3)a 3rd pairing that you don't have to worry about.
It makes massively more sense to go with the potential of 3 solid pairings, as opposed to 2 'okay' pairings and a cluster**** of leftovers for the bottom group. You can swap Ballard/Barker/Alberts/Bieksa around all you want on that bottom-pairing...but every single combination thereof is likely to be a disaster...and we've seen evidence of a lot of those combinations sucking already this year. And it's pretty clear that Edler+Bieksa isn't a viable pairing.