Duanes hit the nail on the head. Your african cichlids are almost fully mature fish, the jaguars are just babies at the moment. The african cichlids will likely shred the baby jags at their current size, and would dominate them until the jaguars were a good bit larger than the africans. And, at that point, the jaguars will likely turn on their aggressors and kill/eat them. Bottom line, in a 120 gallon tank I don't think this is ever going to be a good mix.
A lone jaguar may be OK in a 120, though it is smaller than I would recommend for an adult male, which would be capable of reaching almost 20" of length. A pair would be cramped eventually, may work for a while though. 180 would be about the minimum most experienced keepers would recommend. Lots of screwy info out there on the internet.