I'd say a failsafe way to keep Severum with your Jaguar would be to get 2 around the same size, and keep them together in their own take for a few weeks as both a Quarantine and to let them get used to eachother. In my Experience with Severums they're often quite aggressive towards eachother when first introduced then they settle down and get along fine.
If you've got a pair or two friendly Severums together they'll hopefully look out for each other. As with everything though, it really works on a fish to fish basis so you're going to be looking at some trial and error when they're introduced, and it might not work long term.