The very first tutorial roll will for sure have at least 1 4* at the expense of no 5*. It's the second one after where you can use the Saint Quartz from the login event to try for a 5*. I'm not one to talk since I got a few amazing 5* after barely rerolling, but two 4* Heracles with some support seems pretty strong to me, A leveled one on my friend's list one-rounded one of the higher level daily bosses from full health, and you can merge your two to increase his limit break-y attack thing.
On the other hand, we are supposed to be getting a free 4* (your choice of any of the 4* that the tutorial roll has) and I dunno how much you like the 5* characters. If my fav character were available at launch I'd probably be rerolling til I get him/her since the non "boosted" 5* rate is 1%, and there's never a safer time to reroll than before you invest. 1% means you could be rerolling a long time tho.
Herc is a REALLY good character but is a glass cannon, give him support to mitigate his weakness until he is leveled (and he learns his own innate mitigation) and he will wreck for you. Emiya isn't that great but gets much better once his level cap thing is broken (this can take awhile iirc). Idk much about Altera but she seems to be good at AoE dmg, which is better for farming than big hp bosses but is still decent for a 5*.
