Yeah, if you change the difficulty in your main settings, it affects all modes. There is a way to get into your options through the legacy menu and you can check to see what difficulty your legacy is set at. I accidentally started a legacy after playing in Fight Now on GOAT and was wondering why I was getting my ass kicked.
Your guy is a light heavyweight, so I'd thought you'd only fight light heavyweights in your legacy. Not sure why you'd see heavies in sparring. Usually they look like heavies because the computer seems to only pick the ripped muscular look for the randoms.
I finally got my 10 wins online with one fighter. I'm 10-3 or 10-4. I was using long reach with power punch. My problem was getting caught and stunned all the time and not being able to avoid the knockdown.
So I made a new middleweight and made him tall with short arms. Being tall helps you lean back to avoid punches to the head, because your head is just further away. I made the guy balanced punching to give him a little more speed. The short arms are supposed to make hooks and uppercuts on the inside do more damage. It works, and it is extremely cheap. Basically you just do the bob and weave move once you see your opponent start to throw a jab or straight at a distance. You'll get inside, get the counter window, and your hook will almost always stun him in one shot. Then you just wail away. It's stupid as hell. Do the punch motion during the bob and weave animation and you'll throw the punch immediately as you're coming out of it.
Basically, the whole point of the jab in boxing is ruined. Defensive fighters jab to smother their opponent, or hide another punch. You can't double or triple jab as your opponent is stepping in to keep him at distance. You basically get countered every time because the counter window is set off by a "perfect block", bob and weave or a simple dodge. You can't fight as a pressure fighter because there are too many ways to set off the counter window. I tend to be a boxer/puncher. I like to initiate, but the counters and stuns are just too much. Some of them are warranted, but a lot of them are just because of the huge amount of time the counter window allows for the opponent to land a big shot.
Online you're basically left with the counter puncher. That's the one and only way to play if you want a lot of wins. Be extremely defensive and counter punch using the bob and weave until you get your opponent stunned. Then wail away and go for a knockdown. Body punches off of counters are also great because they seem to drain the entire stamina bar which makes all your other punches do more damage.
The perfect block should be removed from the game. The counter window for any other defensive move should either be removed or shortened.
A lot of the problems stem from footwork. The way the players move, it is too easy to run away in the ring. The way you can spam the jab now, it would be too easy to run and jab your way to victory if they didn't have the obscene counter windows, cause by the various defensive moves.
Don't get me wrong, the game is the best in the series. I'm obviously down on the state of the online play because of people exploiting certain deficiencies in the game, but if you want an awesome fighter to play with your friends, or in legacy mode, you'll be very happy.
Despite my down talk, I'd give this game an 8/10 on my irrelevant scale. It's very good.