How many Dooku's to defeat Palpatine?

If they start on opposite sides of a 40 meter battlefield.

BoTPM
EoTPM
EoRotS
TFU
RotJ
DE

1
2
Hmmmm like 3
6
20
No amount can withstand force storm haxx and thus they all funnel into it and die

3
5
7
30
No amount of dookies can take this

1 to all

BoTPM

1 or 2.

EoTPM

2.

EoRotS

2 or 3. His performance against Yoda (not tiring him, but his duel with him and avoiding being ragdolled) suggest that he's powerful enough to at least contend with EoROTS Sidious. 2 would give him a slim majority at best, while 3 would beat him. The problem here is the distance.
 

TFU

Around the same as EoROTS. 

RotJ

Due to the distance, 5-6.

DE

You should lessen the distance. At this range, Sidious can call upon Force storms and annihilate Dooku. Only a handful of beings can stop these storms, and a tier 8, even one as powerful as Dooku, isn't doing this.

All of these are taking into account distance. Dooku can get close for rounds 1 and 2, and even for 3. However, after that Sidious is just too powerful for Dooku to close the gap and then have the energy/stamina to beat Sidious in sabers.

BoTPM - 2
EoTPM - 2
EoRotS - 3
TFU - 5
RotJ - 10
DE - N/A