I don't know if separate tickets will matter unless JAL doesn't let you OLCI for some reason, forcing you to have to hit the ticket counter, ANA should check you all the way through. Either way, single or separate tickets, you'll have to still recheck your bags, so that should already be accounted for in the 80 minute MCT. Moving between the terminals via landside shuttlebuss is 7 minutes (t3-t2) or 10 minutes (t3-t1).

That said, the problem with multiple tickets is you don't get MCT protections if you miss your domestic flight, so the more time you give between flights the better. But 2 hours, should be sufficient given you will be one of the first people off the plane if you don't get hung up at immigration. In the past on ANA redemptions, if I arrived early in the morning, or after 5pm, coming from LAX immigration was always really quick. If you have a bunch of kids with you though, then you might need to add some more time.

Worth noting that going through domestic security is quite efficient and quick, or at least was pre-pandemic.

Inter-terminal shuttlebus schedule: 無料循環バスのご案内 Free shuttle bus information (tokyo-haneda.com)