Winning the European Cup/CL once have been done by average managers before, so it's hard to tell what Zidane is, only time will tell.
3 wins
Bob Paisley, Liverpool (1977, 1978, 1981)
Carlo Ancelotti, Milan and Real Madrid (2003, 2007, 2014)
2 wins
Jose Villalonga, Real Madrid (1956, 1957)
Luis Carniglia, Real Madrid (1958, 1959)
Bela Guttmann, Benfica (1961, 1962)
Helenio Herrera, Inter (1964, 1965)
Miguel Munoz, Real Madrid (1960, 1966)
Nereo Rocco, Milan (1963, 1969)
Stefan Kovacs, Ajax (1972, 1973)
Dettmar Cramer, Bayern Munich (1975, 1976)
Brian Clough, Nottingham Forest (1979, 1980)
Ernst Happel, Feyenoord and Hamburg (1970, 1983)
Arrigo Sacchi, Milan (1989, 1990)
Ottmar Hitzfeld, Dortmund and Bayern Munich (1997, 2001)
Vicente del Bosque, Real Madrid (2000, 2002)
Sir Alex Ferguson, Manchester United (1999, 2008)
Jose Mourinho, Porto and Inter (2004, 2010)
Pep Guardiola, Barcelona (2009, 2011)
Jupp Heynckes, Real Madrid and Bayern Munich (1998, 2013)
1 win
Jock Stein, Celtic (1967)
Sir Matt Busby, Manchester United (1968)
Rinus Michels, Ajax (1971)
Udo Lattek, Bayern Munich (1974)
Tony Barton, Aston Villa (1982)
Joe Fagan, Liverpool (1984)
Giovanni Trapattoni, Juventus (1985)
Emerich Jenei, Steaua Bucharest (1986)
Artur Jorge, Porto (1987)
Guus Hiddink, PSV Eindhoven (1988)
Ljupko Petrovic, Red Star Belgrade (1991)
Johan Cruyff, Barcelona (1992)
Raymond Goethals, Marseille (1993)
Fabio Capello, Milan (1994)
Louis van Gaal, Ajax (1995)
Marcello Lippi, Juventus (1996)
Rafael Benitez, Liverpool (2005)
Frank Rijkaard, Barcelona (2006)
Roberto Di Matteo, Chelsea (2012)
Luis Enrique, Barcelona (2015)
Zinedine Zidane, Real Madrid (2016)