Originally Posted by
Bovan
Arcane Shot is a filler you only use when you have focus to burn* and casting a Cobra Shot will cause you to cap on focus.
*Clarification on ''focus to burn''. Basically if you have enough focus for your next important shot you need to use on cooldown like Kill Command, Chimera Shot, Explosive Shot and so forth, then you can use an Arcane Shot. You should never be standing around doing nothing for even a second so you either fill downtimes between shots with Arcane Shots or Cobra Shots.