So, I ran a few games with each of the new heroes. I have both at rep 1.
Highlander (B+)...
You need to use his defensive stance to go into his offensive stance mixups, but his offensive stance is where his bread is buttered. Even if you land a parry, follow up from his defensive stance and it will push your opponent back enough to set you up to go into his offensive stance - which is done by holding R trigger.His moves from his defensive stance all push your opponent to a range where their quick attacks and GB will whiff - so you can wait to sit on a parry - or - hold R trigger to go into his offensive stance. From there, you can quick attack with RB, which works like an armored jab, unblockable kick with X, which has to be dodged because its unblockable and quick, or let his unblockable heavy go, which hits anyone dodging and has to be parried. So, rather than a 50-50, its more like rock-paper-scizzors. You need to start in his defensive stance though and commit to an attack to space it perfectly or just be patient and walk them there, but he is very slow - hence the need for his defensive stance attacks spacing it perfectly if not parried or countered. Some people think he's only good in one on one while others think he's only good in team fights. He's solid in both, but they take different skill-sets. He doesn't close well in team fights, so you have to pick your spots - but a cornered opponent is a dead opponent if you know what your doing. I'm still pretty new to him, but I think HL is upper-mid tier.
Gladiator (A)...
Pester them with quick attacks until they try to move in. Then, he shines. He has a great poking game, but his counter game is where his damage lies. His light attack combos (or just one) into his stab or foot stab to keep them bleeding or to flank them. If they dodge those, GB or let loose his heavy as either will effectively punish dodging. GB opens them up to more punishment, but heavy is quicker and has more reach. I'm pretty new to Gladiator, but I think he's top tier. If you like Valkyrie or Centurion, you should give this character a good long look.