Mega Man leads with going through various weapons to try to find a weakness or whatever his most efficient weapon has to be in taking down enemies. He's also prone to dodging attacks, and combined with the fact that Lance is almost always stationary on the ground to the point where he struggles to dodge enemies on a similar speed to him without his jet, he's more likely to be hit. Also, if Mega Man dies, he can come back with spare bodies. Given how he can carry 99 of them, you'd need to kill him that amount of times to for him to die for good. And if Lance dies at any point, the battle will just reset back to the beginning where Rock will have his 99 lives as if nothing happened.
Which is hard for him to do on the ground against someone on the same speed as him and with a good aim. And yes Lance has his skills, but they've all been shown to be dodgeable.
Mega Man is the type to switch to the most efficient weapons for all the enemies and forms he faces, so this isn't much of an issue for him.
Not the first time Mega Man has had to deal with more than one opponent in battle, especially since he has some AoE attacks to handle just that. Hell, with how the Neon Valkyrie functions, it acts similar to many Wily Machines that Mega Man fights regularly.
Because he never at any point gets his jet in that game. Combined with the fact that EBF5 is a reboot to the entire series, even if he got his memory of the past games back, it still doesn't change the fact that he doesn't have his jet.
Which again, are dodgeable. And depending on what armors and weapons Lance has on, it's going to change his resistances, which could potentially leave him vulnerable to moves like Flash Stopper, Time Stopper, Gravity Hold (Which doubles as BFR that the player controlling Lance can't reset from), Spark Shock, and even getting transmuted into a 1-Up with the M-Tank (Which Lance can never resist no matter what armor he has on).
Fair on the instant death part. But like I said, they dodgeable to which Mega Man's entire strategy is to find patterns when avoiding attacks proficiently. Also, Mega Man has fought and taken hits from magic users before (In the form of Magic Man).
AoE attacks that have been shown to be dodgeable in the game. I have never neglected those. Fair point on the antimatter flux, but Mega Man has had experience dealing with explosive users. As much as scanning Mega Man is useful for Lance, Mega Man has been used to fighting opponents who know him.
More specifically, gravity pushing him down/lifting him up. He's never been shown to resist having his gravitational direction reversed upside down. And it's possible for him to still get affected by the attack if he's not wearing the gear that resists said attack, and speaking which, Magic Card allows Mega Man to grab items, so he has the potential to disarm Lance with it. As for Flash Stopper, it emits a light bright enough to stun enemies, and also layered since Bright Man using that weapon has been shown to affect Mega Man with it despite how he could take hits and still move from Spark Man's Spark Shock which can immobilize enemies.
He's got the Speed Gear to enhance his own speed when needed, and if Lance isn't wearing any stun resistant gear, he can be affected by time-based weapons.
