If you mean "half the defenseman Walman is" you are probably right. I don't see Johansson as anything more than a bottom pair guy at the NHL level. He is in his D+5 and while he is succeeding at the AHL level, he isn't exactly lighting it on fire either. It's more likely he's back in the SHL in 3 years than holding down a spot on an NHL roster.
In four years our D core will probably be some combination of Seider, Walman, Chiarot, Edvinsson, ASP, Wallinder; Chiarot will be on his way off the roster.
He is routinely brought up as of right now being better and more ready that edvinsson from teammates (mazur specifically). Horcoff said himself that he was the first callup last year if anything happened in detroit but then got the season ending injury, so edvinsson came up. (was on video when he said it).
He has a much higher floor than edvinsson, but Edvinsson has a much higher ceiling. Aljo, if you give him the same opportunity as walman did last year, would be exactly as good as walman is right now, maybe slightly less. Walman has the shot that outdoes aljo, but aljo is much more capable defensively, is much better with the first pass. Being D+5 doesn't mean much when you are talking about him being farmed in SHL and has been on NA ice for a season and a half. He's not a big goal producer, but he is much more stable on defense by not making much mistakes. Walman is great a shot blocking and his windup but he is not as solid on defense as some may believe.
You guys are sleeping on aljo and thats fine. He is more than half as good as walman is right now as we speak. And he hasn't touched the nhl yet.