Ever so slightly more than two i'm afraid ....
Cowdrey v South Africa 1960 (england won the series 3-0)
Hon FS Jackson v Aus 1905 (Eng 2-0)
M.Taylor v England 1998/9 (Aus 3-1)
Hassett v Eng 1953 (Eng 1-0)
Noble v Eng 1909 (Aus 2-1)
for West Indies
CH Lloyd v India 1983 (WI 2-0)
Sobers v NZ 1971-2 (0-0)
Sobers (again) v Eng 1966 (WI 3-1)
Goddard v India 1948/9 (WI 1-0)
Nawab of Pataudi jnr v Eng 1963/4 (0-0)
In addition to the above
May (3) and Cowdrey (2) won all 5 tosses for Eng v WI in 1959/60 (Eng 1-0).
Your question implies that the series length is only 5 matches ... here are the additional captains that have won 5 tosses in series of more than 5 games!
Fletcher 5/6 v India 1981/2 (Ind 1-0)
Taylor 5/6 v England 1997 (Aus 4-1)
Yallop 5/6 v England 1978/9 (Eng 5-1)
GS Chappell 5/6 v WI 1975/6 (Aus 5-1)
There might be the odd error in the above and it might not be completely exhaustive but reckon it's pretty much okay.
The question you might've been asked is which two England captains have won all fice tosses in a test series or which two captains have won five tosses in a series twice (sobers and taylor)
One things for sure - Graham Yallop didn't have much joy with his decision making once he'd won the toss