Very interesting match. Both Haggar and Max are capable of beating street thugs as well. As I remember, stage bosses in Streets of Rage 2 were less durable and weaker than Final Fight bosses, but that shouldn't decide who would win this match. While Max has no actual story background and is just limited to SoR, Haggar was a pro-wrestler for years and is quite experienced in wrestling, so that's why he would most likely beat Max.
the 2 reasons i can't decide is
1.Max has a slide move
2.Max can sacrifice a little health for a charge attack or a spin that can break grapple locks
but Mike Hagger has more Range using his fists and also has an anti-grapple lock move that costs a little health
3.both tie in jumping attacks
in a close fight Hagger has the edge...but does Max have enough distance advantage?