Looks good.
Some thoughts:
Wizard Apprentices can only get the number one spell and the hereditary. Spells cannot normally be cast multiple times in the same phase, even by different wizards. The DL hereditary is fairly unique with the replicable tag which allows it to be cast multiple times in the same phase by different wizards. If that's your plan, great. If your plan was to cast the Divination number one spell over and over, that's not gonna work. However, they would still count as Divination wizards for The Conclave rule.
The next two are just my opinions, you can take them or leave them.
Personally, I wouldn't run a character with a "chaff" unit like Sirens. That just makes the unit more expensive if you need to sacrifice it.
Also, I wouldn't join characters to the Mageblight Gremlins as then they can't use their special Ambush rule. But the hard target can be useful as a defence. Oddly enough, shooting hits can't be distributed to a character in that unit, if there are enough (5) models as they are both standard beast, even though they are on different base sizes. Although I see now that the max unit size is four, so that'll never happen.
Otherwise, it looks good! Can't wait to see it on the table.