Heres some Pros and cons of Skorpion and mp5 (& vector) in Web version
Skorpion :
Pros :
Cons :
In early-game, the high rate of fire can make your ammo deplete faster and can potentially make you run out of money
Poor Accuracy, it better to be used as a short range weapons.
MP5 (& Vector) :
High Accuracy
Increased Power
Cons :
Trades RoF for power and range.
Low rate of fire, significantly affecting DPS, unless you want to Eco.
(Vector only) Has 10 less ammo.