I can effectively fight off most single opponents even though I picked a tiny female at character creation. Obviously that's with maxed out stats, but that still means that screaming is not the only effective tactic, even if you are a tiny malnourished orphan girl. I mean, you're starting out as a malnourished orphan who is either unusually small, small, average, or larger than average. There is no unusually large orphan option. If you want to be some sort of badass orphan who can beat down multiple rapists at once then you need to have not only work your ass off, but also have won the genetic lottery. If you choose not to have won the genetic lottery, then you need to work your ass off to beat the shit out off an average rapist. But the point is: you CAN beat the shit out off an average rapist even if you are a tiny malnourished orphan, and I think that is more than fair.
I think tiny and weak is how the player is intended to feel, so I agree the balance isn't wrong. I don't want folks to think I was complaining: I imagine that you can, as you've described, get G.I. Joe enough to fight off attackers. Heck, small folks and children in the real world can do it pretty well. But I think the average player expects to eventually become badass enough to win every battle, which isn't really the intent in this one.
That's why I don't really think of the "combat" in this game as combat--it's like one of those horror games with a combat system but not enough resources to just fight through the entire game. I read or heard somewhere about a guy who was thinking of making a survival game with a small, weak, and untrainted protagonist. At one point in the game you find a shotgun, but your character didn't know how to use correctly. You could kill a thing with it, but you'd only ever find one or two shells, and if you were to fire it while moving your character would break a wrist, which was more or less game over. You could get an axe, but it took like three seconds to swing it, making it more or less useless. The whole idea is that you wouldn't really ever have an effective weapon, because you were supposed to be avoiding fights. Dunno if the guy ever got around to making it. Anyhow, I'm rambling.
In this game, I think it's working as intended for the average encounter to have the player at a huge or even insurmountable disadvantage without a player built heavily for fighting. Given the game's pace feels kinda slow, I imagine a lot of players won't put in the time to grind up physique.
Come to think of it, since this is a porn game then being overpowered and raped is probably the draw for a good chunk of the player base.