Attacking the Carthaginians early is definitely the right way to go. I tried to be nice to them once as Numidia and ally against the Romans and Spanish. Carthage attacked me with everything they had and I had to give up the campaign after losing Cirta and Tingi before I got off the ground.

At this stage I would advise doing all you can to break the Scipii and avoid all out war with the nightmare that is Egypt. I have always started a Numidia campaign dreaming of an early foray into the Nile, but have never been able to produce anything to deal with Egypt at that early stage. When I have tried to hold Siwa at all costs I have found that Egypt just keeps throwing bigger and better stacks at it until you are overwhelmed, regardless of their obvious threats on other fronts. In all my campaigns as Egyptian neighbours they seem to forget everyone else around and throw everything at you.

As you cannot avoid a war with all of the Roman factions from an early stage, and once started it can only be ended with their destruction or yours, I would recommend doing all you can to avoid war with Egypt as well. Take them out later when you have plenty of camels and Balearic slingers who simply crucify chariots in a very gratifying way and very quickly.

The Scipii above all you must hate with a passion. They must learn that Numidians do not take kindly to dissembling tricksters who set fire to their camels during the hours of darkness!