Well some of y'all may be weary of this; I think this harks back to the mis-understanding over Kell Bailoch's ROF, but here goes.

Just because a Leviathan, (or a Redeemer), is said to have a ROF of 3, that's not really true? We Amish see ROF3, we fire three times. If it said ROF2, we'd fire two times; y'all see how that works?

But nnnnnnnnnnnnnnnoooooooooooo. Having discussed this at Dark Sphere, the interpretation of the chaps there of ROF3 is:
Shot number 1 is gratis.
Shot number 2 is an 'additional shot' and will require the expenditure of 1 Focus.
Shot number 3 is an 'additional shot' and will require the expenditure of 1 Focus.
And that's yer lot.

Zo...I allocate 3 Focus to my Leviathan, (which is the maximum it can be allocated), and to fire three times, I say goodbye to two of them. That leaves one Focus to boost either the RAT, or the Damage, of one of those shots; allocated when I take that shot.
It would be ssssssssssssssoooooooooo much clearer if instead of '3' it said 1A2 (for Leviathan/Redeemer), 1A1 for the Charger, 1D1 for Long Rifles, and...Kell Bailoch. The A means Additional shot requiring the expenditure of 1 focus; D means additional shot dependent on the figure forfeiting it's movement for Aiming (Dualshot).

Y'know I found it curious that Cryx' premier shooty warjack had a RAT<its MAT, but figured that the ROF3 implied 'spray and pray'; even more so in the case of the Redeemer. As it stands, (and seeing as I brought up the subject of maths),

Leviathan costs 9, Range+Advance=18", POW13, 1 shot, 1 target.
2 Defilers cost 10. Range+Advance=15" POW12, 2 shots, rolls against every valid target caught by spray template. Oh and two Arc Nodes to de-buff target(s)for next shot, with ?Parasite and/or Scourge.

Choice - two Defilers, or one Leviathan? Nah, I'll take all 3 of them... Of course for the melee thang it's two Slayers for one DJ, but that's another post.

OR.

I stick with Magnus, and buy as many Renegades as possible...