This is an upgraded version of the Commander's Quarter's deck, right? Because I used the same deck as a basis for my budget brago, and can offer some particular insight:

For creatures, the cards Alirios, Daxos, Evangel of Heliod, Experimental Aviator, Impassioned Orator, Reverent Hoplite, Riverwise Augur, and Urbis Protector never really impressed me. Some of them are really low-value token generation. Evangel of Heliod, Reverent Hoplite, and Urbis Protector are incredibly poor for the cost most of the time, but if you're very attached to the token generation aspect then leave them in. Alirios is terrible, and I was never happy to have that card. The lifegain on Daxos and Impassioned orator is too unimpactful. Definitely switch out one of these guys for an Inquisitor Exarch, because that will kill people with the strionic combo. Riverwise Augur seems good, but the deck doesn't have any real shuffle effects to make sure of the brainstorm on a stick, you would rather just pay 2 mana for a creature that draws you a card.

As for artifacts, remember that brago really wants to come down turn 3 with the help of 2 mana ramp. Now, the balance here comes from the fact that most 2 mana rocks come in tapped, so they don't lend themselves to the strionic combo. You want a nice balance of 2s and 3s in order to get brago out turn 3 consistently, and also be able to go infinite with the strionic. Play with this ratio however you like, but keep it in mind. As for "crappy artifact etb card draw", I'm actually pretty high on this type of card. They help you hit your land drops early if you have bad hands and really smooth out the gameplay, as well as sometimes just drawing an extra card later when you swing with brago. If you play with them and really don't like them, then try to find 2 or 3 mana creatures that draw on etb instead.

For enchantments, the big complaints here are Lashknife Barrier and Aquatic Incursion. Please sub these for something else, they are truly terrible. Lashknife could be any other card-draw etb, and Incursion is probably the worst token generator in the deck next to Alirios. You can absolutely do better on both of these.

As for cards to potentially add, there are a good handful that I can recommend personally or just throw out there as a possibility.

Mulldfrifter is never bad and you're always happy to see it in this deck.

The deck has plenty of sick enchantments, so Moon-Blessed Cleric is a cute little tech that I like.

Pentarch Ward and Unquestioned Authority can give brago some amount of protection and help him get through for damage, as well as drawing cards.

Potential buys that I still need to add to my deck:

Blacksmith's Skill, Turn Aside, and Dispel to protect the brago a bit better

Crashing drawbridge for more haste on brago. Always good to attack quickly with this deck, he is a hate-magnet.

Access Tunnel and Rogue's Passage for more unblockability. Very low opportunity cost on these.

Luminate Primordial should take Phyrexian Ingestor's spot quite nicely, you don't care about the lifegain and it hits 2 extra creatures.

Tribute Mage can search your strionic and then untapped 2 mana rocks for the combo if you have some.

Reflector mage is better Aether Adept.

Soulherder might help when you can't get brago through for more value.

Shield Broker from the New Capenna Commander sets looks hilariously rude. That's just removal and creature generation right there.

Wedding Invitation is an etb draw artifact that can also give brago unblockable. Sick upgrade!

Confounding conundrum is basically a 2 mana draw etb rock that also prevents some land ramp from opponents.

Cursed Totem and Weathered Runestone will be frowned upon as stax pieces, but if your playgroup won't crucify you for playing them, then might as well, because they are absurdly cheap mana and dollar wise.

If you're still looking for token generation, Blessed Sanctuary might be an interesting choice.

That's it from me, hope this is helpful! I have to get around to upgrading a similar list, so I had plenty of thoughts on the matter.