If the tokens are creature tokens and can exist in different states, than i think bringing a couple is helpful.
one token + dice for each untapped and tapped elemental token maybe. you could go above and beyond by including tokens that are summoning sick and stuff like that
I usually use 3 pyro tokens in this configuration, unless the board state gets confusing enough to warrant tokens for every elemental
I'd go with 4 tokens. 4 is often enough to represent all the tokens you need. If you need more, just put dice on them and you have enough to represent all the tapped, untapped, and opponent controlled tapped and untapped (assuming they have a way to steal tokens). There aren't any other configurations you'd need to represent with more than 4 tokens.
Dice is lame. Take 10 tokens with you and some d20 in case things get out of control. Some nice tokens btw. If you are already playing paper vintage you should make some effort for things to look cool. That should be an official format rule, even for unofficial games.
But yeah, at least 3 + dices to represent different states in case you have no shame.
The bare minimum for me is 2(one for untapped and 1 for tapped) I bring 2 Gideon tokens for Miracles in Legacy for example. But that's because Gideon rarely produces a bunch of tokens.
I bring some good 9-10 Monk tokens too, and that's in Legacy, where Mentor tends to get way less out of hand. Also 4-5 Angel tokens for Entreat the Angels.
I prefer to have a clean board state, and with large token generators like Mentor and Pyromancer things tend to get confusing and I prefer to have tokens for everything. Also helps your opponent concede because he can clearly see he's overwhelmed.