Actually I was surprised that Hagg was selected for the team. We all know that there were bad feelings between his coaches and him last year and was the reason that he came over to the Phantoms. The Swedes build a team and a strategy to win this tournament. Its to being done to develop players or show off their abilities. Some guys are good for that-a seven game series officiated in a tricky tacky way. Others are built for the NHL. Hagg is the latter.
They really had to... he was clearly the best D man available for the team this year with his track record. Frankly he is the best defensive defenceman on the roster and arguably the most rounded.
His role on the team as last year is to go up vs the oppositions best every shift and take up PK minutes... Sweden do not have another D man capable of doing so, even though Hagg has been poor so far he will continue to be played in that way as they have no alternatives. If he is only +0 to -1 every night frankly Sweden are happy with that in the 20+ minutes he plays.
Aho is undersized and still a defensive liability at times. (even though I really like him and wanted the Flyers to take him late last year.)
Norrell has a lot of tools but they have never really translated... and he has performed worse than Hagg at every level.
Forsling is a solid all round D man, I quite like his game, could end up being an NHL #4, but likely not more.
Lagesson is a poorish skater with solid D but no real offensive touch.
Englund is a physical D man who is solid on D but not much offence... he does skate pretty well for his size though and has some upside.
Bergman has a lot of tools as well, but has never really came up and showed his ability level vs top opposition.
The Swedes want to win, as you say... and Hagg is the furthest of the group along in his development, has the best track record, is the most physically mature and plays more minutes in a mens league than any of the others. (heck, not all of them have played 5 games in mens leagues so far.)