I really enjoy watching my predators chase and eat live meat. It makes me smile to see them so enthusiastic about food.
I do still feed pellets to them, but only once in a while.
The key to having your arowana to eating a huge variety of food is to introduce it to them from a young age. Now mine eats centipedes, frogs, fishes, meat, pellets, crickets, superworms, etc.
But do continue to feed them pellets before you feed the live food to make sure they remember that pellets are still to be eaten. Else they get addicted to live food and you gotta starve them.
For small arowanas, I don't recommend you starve them to get them to eat pellets.
Once they reach 6" or so, you can starve them so that they will accept pellets. I won't worry about them not eating for more than a couple of weak. They ain't as weak as you think. But it will be up to each individual to judge if the starving should carry on. Observe the fish. Although fishes can be starved for some time, do remember that once past a certain limit, they won't eat even if you throw in feeders, so don't overdo on the starving part.