Heracles the best tutorial 4*?

Yes, Heracles is the best.
The second place is not that obvious. Opinions are split between Emiya and Tamamo Cat as far as I know. Though Emiya is probably better in the long term.
The main problem in terms of reroll is the bottom end. You don't want Stheno or Siegfried. And probably Chevalier d'Eon either.
Stheno is famously bad, Siegfried is only ever useful against dragons (though he has a lot of hp), and Chevalier isn't really useful either.
Of course, as many people have said on this site over and over again, go for the ones you like. It won't hurt you in the long term.

Heracles is the best indeed.
He can solo the entire Camelot, can solo the heck out of Goetia, isn't reliant on supports, fits in any team comp as mess cleaner, hard to find his flaws, especially when you have his bond CE
I would call Emiya the second best, but he needs his rank up quests for that, so, he will be a bit lackluster in the beginning

Just some info about the other notable 4* servants in the tutorial summon
Tamamo Cat, will help you a lot in the beginning with farming
Carmilla, not many people talk about her, she is too unpopular, but she is actually a really solid np spammer servant with a quite nasty np herself
Liz is pretty much a solid farming servant, but Tamamo Cat is probably better

The rest of them are too much for new players to handle, so, unless you want challenge, reroll the hell away from them

Heracles is best when his bond level 10

Herc is definitely the best, having a high damage output and strong survivability
Tamacat is better right now, having high damage output, but her NP hinders her later on because of the stun
EMIYA is meh right now, but when he gets his strengthening, he is a pretty decent star generator and his NP will hit a bit harder (he has a pretty weak AoE, but strengthening gives him a skill that boosts buster performance)