High Vampire Max Atk
5 GSR High Vampire 87496.6 Atk + Team Bonus 96246.25
3 GSR High Vampire 62497.5 ATk + Team Bonus 69997.2
3 after 1 Calamity Boost = 343736.25 Atk + Team Bonus 384984.6
4 GSR High Vampire 74997 Atk + Team Bonus 82496.7
4 after 1 Calamity Boost = 412483.5 Atk + Team Bonus 453731.85
Faster Deaths = 3 High Vampire
Safety in Numbers = 4 High Vampire
5 is too weak to kill AW or really be useful for duel/AUB/defense
Also +30% Unit Bonus for Godlike Rare Force and 3 Dark Unit which is 7499.7 starting off.
+35% 8749.65 for 5 GSR High Vampire
I think that's everything. Once Awakening is allowed for High Vampire you can make some pretty good AW/EH teams I think. I would go for 3 + Skill Unleash + Buffer, but I know lots of people want to always have a Skill Nullify on the team. Of course all of this is also assuming max attack cards and not calculating if you wanted a different main attacker GUR self buff instead of team buff. I just prefer team buff and preferably ATK and DEF buff combined.
Adding some Speedster stats since it was requested.
Speedster max atk 39999 max skill lvl
3 GSR High Vampire Boost +150% static
Starting Atk 99997.5 added + 30% for GRF and DarkX3 unit bonus - 111997.2
1st Boost 154996.125 - 173595.66
2nd Boost 240243.994 - 269073.273
3rd Boost 372378.19 - 417063.573
4th Boost 577186.195 - 646448.538
5th Boost 894638.6 - 1001995.234 (999999)
No team buff strictly necessary, though it Speeds it up a little. ;^)