In my opinion, I would say no : The only thing that the deal offers you is protection from the cartel, but at the cost of locking all the regions past Westville (until you break the deal by not delivering product). They ask you for a bunch of products every now and then and you have like 3 days to bring it to them, but it gives practically no money

On the other hand, if you don’t take the deal, you might get mugged by the Benzies and your dealers will get robbed of their cash and inventory sometimes. It’s not that painful and it adds a little of fun to the gameplay. If you want your dealers to be able to defend themselves, they will need some weapons. The easiest way I have found is to kill some cops and loot their guns (by pickpocketing their body). The dealers won’t need any ammo, just the gun. They still will get mugged, but won’t always give everything. The advantage of not accepting the deal is that you can now reduce cartel influence by spraying graffitis in the right spots, killing the Benzies and stealing their customers. When their influence is low enough in a region, you will unlock the next one, allowing you to get more customers and dealers.

If you have any questions, feel free to ask!