Splitting the pool, Spellcasting Options

[Lansdren]

Can I get some advice / ruling on splitting the spellcasting pool.

Am I right in this?

Mage M5 SC6 Specialised for combat spells +2 Mentor Sprit Wise Warrior +2 R4 Spellcasting focus +4

Normal pool would be 19
if split between two targets (casting a mana bolt at two guards similtaniously)
G1 5 from base pool (5+6/2) +2 Specialised +2 Mentor +4 Plus focus Total 13
G2 6 from base pool (5+6/2) +2 Specialised +2 Mentor +4 Plus focus Total 14

Rather then just
G1 10
G2 9

Because the specialisations, mentor spirits and focuses are modifiers to the skill and are added after the base split

Or is the focus bonus split too? Its being used at the same time in the same complex action to do both spells but am I understanding this right. I was sure of it when I did it last session but now I'm having doubts