Possibilities of island maps are Ror Shock, Metal Isles, Seven Seas etc. Which one were you playing?
Possibilities for KBot/vehicle attacks would be: Hulks/Envoys (ship transports),Turtles/Bears (hovercraft transports) and Atlases/Valkyries (air transports). Air could be used after the initial KBot/Vehicle attack took out anti-air emplacements.
If you build at least one more nuke silo than your opponent has anti-nukes some will get through. Handy for dealing the finishing blow, or once again used after KBots/Vehicles (transported) took out anti nukes (Fortitudes/Protectors).
In any ballistic weapon (Bertha, Timmy, Vulcan, Buzzsaw etc) to get extended range order it to attack just in front of the unit. It will raise it's barrel to the highest point depending on where you clicked and will fire much further than normal. Take some practice first but you can eventually vary the range and angle depending on where you choose to attack just in front of the unit. Works best for Buzzsaws/Vulcans.