Zidlicky is not a legit top 4 guy though, even if he played those minutes in New Jersey. While he does have a different skillset, it's ultimately just more of the same in terms of how he slots into the line-up. The Bruins already have 3 RHD that are bottom-pairing guys.
Is he better than Irwin/Trotman, if yes then he would make us better, like it has been said many many times we need a D-player who can clear the puck, via skating or passing and Zid could be a huge help for that, he can also give you +30points which we need badly if we want to be in the playoffs and he could possible limit Chara's minutes which would be huge for our next 2 seasons.
We could definitely use Zid's passing and he shouldn't be too expensive to sign, could leave us 2M in cap space if we sign him around 2M.
It's pretty clear now that Sweeney is not going to star the season with the D-players we have so now it's just figuring our who helps us the most&fits the best.
I kind of like Chara-Ehrhoff-Krug 1year LD goup and if Seids the big if can improve a lot the RD side could be okay, but do I like it more than Franson for 2years I don't know, with 1y deal we'd still be 2 top4D's short next offseason.
1) Franson on a max3y deal, if not then Ehrhoff for 1year deal and Zid is the 3rd backup of a backup option. But no matter which one we'd get our blueline would get better and I would say welcome. Best option would be not to take anyone but we are where we are right now and have to get through this somehow.