Is it better to be "hung like a pike" or "hung like a stickleback"?

More from the British movie The Football Factory. The background is that the main character and his best friend have picked up these two girls at a bar; things proceed swimmingly, and the two head over to the girls' house for some hanky-panky. Unfortunately for the guys, both have imbibed a little too much alcohol, and they promptly pass out in drunken stupor, before any intercourse. The two girls seem mutually disappointed; one calls out to the other across rooms,

Shame! He's hung like a pike in 'ere.

And the other replies,

Good for you. I've got stickleback in 'ere.

I'm guessing the meaning here relates to the properties of the two fish, but I don't know anything about them, and don't understand what hung means in this sentence.

"Hung" in this context means "possessing a penis", with the implication that the penis in question is of some particular size. "Hung like a horse" or "hung like a mouse" means wielding an organ of (respectively) great or negligible dimensions.

To be hung like some fish means your penis is purportedly comparable not to that fish's penis, but to the whole fish.

A Northern pike (Esox lucius), the species of pike most familiar to your average Brit, grows up to 150 centimeters (59 inches) long. The three-spined stickleback (Gasterosteus aculeatus) generally ranges from six to 10 centimeters (two to four inches) long and proportionately slender.

To the original question, which is better, tastes vary but I'm guessing the latter would be innocuous, though perhaps disappointing. The former would be outright dangerous.