I dunno if I have the time to give a real effortpost, but it's not that they have strengths and weaknesses. Or that some people on the same side think the enemy is strong yet others disagree and think the enemy is weak.

It's that, from a single narrative source, the enemy is both far too strong and far too weak at the same time.

It's that they're contradictory, that they're needed for fascism, and that they'll lead to the fascists' eventual demise, because they don't know how to objectively size up and effectively fight against, their opponents, in the long term.

It's needed by fascism because they need to be scared for it to work. Fascists try to pretend their aggression is actually self defense. They need to feel afraid of them, to posit them as an existential threat, to their existence and/or their way of life, hence the enemy being incredibly strong. Yet need to also feel superior to them, feel like they can win, and feel like the superior race/class/caste/nationality/culture/etc, hence the enemy being incredibly weak.

For instance, antifa are all ineffective limp wristed girly men who can't even throw bricks because they're too heavy, while also all being highly trained assassins at the same time.

Yes, this sort of thing can/does pop up on the left, though not as much, and yes, it's just as bad when people who self identify as socialists do it.