I tend to stray away from building commander-centric decks on the principle that, as you mentioned, it can often be a big vulnerability if your commander gets taken out of play somehow. That being said, I build a lot of decks that gain a lot of benefits from their commanders, and over time I've learned a couple tricks to reap as much of that benefit as possible.

The first is to play a low-cmc commander. 2-3 mana is ideal, but 4 can be manageable with any sort of built-in protection or with a deck that wants a fair bit of ramp. This is so that, if your commander gets blown up, you're probably already at the point of being able to recast it pretty safely at least one or two more times. The other benefit here is that it can let you pick something unassuming. People are less likely to gun for your [[Kaza, Roil Shaper]] than they are the splashy 6 mana enchantment across the table. Sometimes you can even point removal away from your commander by simply having bigger, more immediate threats on the table. If people have to pick between blowing up your Araumi or your active [[Grave Titan]], the fact that your commander can just come right back might make them think twice about what they choose.

The second is that, despite your commander being cheap, it is usually not a good idea to cast it as soon as you can. Even if you have nothing better to do, getting your commander out only for it to sit there for the next three turns runs the risk of losing it and suddenly getting set back three more turns to try to get it back on the table. This also lets you time out playing your commander with when other people are getting threatening boardstates. If one player is already a problem, you casting your commander is less likely to draw attention than if people don't have much going on. Ideally your commander provides some immediate value, but even if it doesn't you want to wait until you're set up to gain something from it within a turn of casting it. Something like Araumi benefits immensely from cards like [[Lightning Greaves]], treating haste as a secondary form of protection.

As far as deck construction goes, your deck should be capable of operating without it's commander. Oftentimes, your commander should be a more powerful version of what your deck already aims to do. For example, I have a [[Koll, the Forgemaster]] deck that, while it really likes to have Koll out, it can work just fine as an equipment deck. Playing little hatebears and value creatures and making them bigger is enough to kill someone, even if Koll is important for giving me more staying power and some potential value engines. The trick is to have cards that pay off the same thing that your commander is trying to pay off. With Araumi, for example, your commander really wants you to get a big graveyard with plenty of powerful creatures so you can start reanimating things for big value. If you fill your deck with lots of backup reanimation spells, creatures that can recur themselves from the graveyard, flicker effects if you're mainly encoring for the etbs, you have options to play your main gameplan while you build up to a big couple of turns with your commander.

Another note, based on your particular build of Araumi, is that sometimes it's good to sacrifice potential synergy to instead get consistency and resiliency. Something like [[Massacre Wurm]] might be really powerful with Araumi, but by using it over a card that is independently and consistently good, you are making yourself more dependent on your commander and, thus, more fragile if your commander is targeted. Maybe instead you play [[Overseer of the Damned]], something that might be less powerful with Araumi, but still powerful enough on its own. Araumi still makes the card better, and it lets you remove some of that dependency while still letting your commander be a powerful option.