Questions on Help and conflict

Is there a limit on help dice accepted?

In conflict with multiple teams on a side, and two teams both oppose the same opponent in a Vs test, how many dice go across?

EG: Team A is 4 mice, Team B is two mice, both face the one snake; A&B both attack, snake defends. B’s current mouse, due to higher skill, makes the roll, he grabs a help die from his partner, but does he get 1d or 4d from Team A’s help? (The are all charging and surrounding said snake to slice it to death…)

1D from the mouse on team A who is taking the action. The other mice on team A can only help the mouse on their team who is making the action.