I don't understand the hard-on over Slave 1 being in the fight. Does Venom-Spider have to take it out too, or is it still Spider-man Vs Jango?
If the later, there's really no reason to believe he couldn't just avoid the blaster fire and rapidly make his way to Jango for a kill, considering he's amped up with the symbiote and would be faster, stonger and more agile.