Kalani, you are leaving out the part where you need to explain the elephant in the room.
'I wanna play a necromancer!' is usually code for 'I want to have undead servants following me around!'
You should explain how Animate Dead works in AL....ie that it basically doesn't. The point of the necromancer bonuses is that they can keep more undead buddies around, but AL basically chops off your undead hoard at the end of every session...every game your guys are dead again and you have to cast the spell again. Whereas in a normal game, you would just re-up the casting and build up your army over a few days. But AL doesn't let you because there is no accounting for time spent in between missions. You might get a lenient DM to let you, but its technically against the rules as far as I know.
The PHB states that casting animate dead is evil, and that only very evil people would do it regularly. So there is a little bit of wiggle room, but not much.