https://www.ti.com/lit/gpn/bq77908a

https://www.diodes.com/assets/Datasheets/products_inactive_d...

Look at the reference circuits, it's a pair of antiserial NMOS on the negative pole.

(Those 2 protection circuits are at the opposite ends of complexity & features)

To be clear, using 2 PMOS on the positive pole is also quite common, my choice of words with "standard best practice" might be a bit misleading.

> use bus bars to minimize wiring resistance.

Those come after the protection circuit, there should always be 2 MOSFETs in series with the individual Li-Ion cell in a design like this (specifically: user swappable cell).

(Protecting paralleled cells together is kinda nonsensical because you also want to protect them from each other, I don't think I've ever seen a 2P combined protection circuit.)

Those datasheets show creating a series pack/cell. They don't show the circuitry to then parallel the packs together.

I guess I need to do more research on this.

> Those datasheets show creating a series pack/cell.

You seem to only have looked at the TI one, the Diodes one is for a single cell.

& if the cells are "permanently" connected in a pack, you wouldn't have individual cell protection and just have them properly balanced before connecting them in factory.

> parallel the packs together

You parallel cells, not packs.