There is tax gaming tax in
Vanuatu.
Do the founders have experience driving gambling traffic from all over the world? Do they know how to strike good deals with affiliate websites?
Most successful casinos focus on specific markets. Start out with one or a few core markets and then grow. The broader your marketing spend, the less you have to spend per market, which means you won't rank highly on affiliate websites that target a certain country.
Say you have one million USD to spend on marketing. Do you spend 50,000 USD on 20 different countries (which will get you mid/low tier ranking on affiliate websites) or do you spend 750,000 USD on one market (getting and keeping a top spot) and 250,000 USD on a smaller market (getting top spot for a short period)?
Vanuatu is not a common license, which is going to be a problem. Payment processors and banks/EMIs aren't familiar with the license. They see Curacao, Malta, Isle of Man,
Estonia, Anjouan, and so on. There's a reason no one with industry experience would go for Vanuatu. How many Vanuatu licensed online casinos do you know of?
Are you sure the license is legitimate? Have you independently (not through your agent/service provider) verified it? There are unfortunately a lot of people selling fake licenses in places like Vanuatu and if you don't have a lot of industry experience, it's hard to tell them apart. I don't mean to insinuate anything, just asking because it'll help figure out what options you migh thave.
It's good you ask because those are examples of processors not very commonly used in online gambling (if they support them at all). Access to good payment service providers is usually limited to introductions and referrals, rather than publicly discussed. It's just how the industry works. Many payment processors don't need/want to be seen in the open.
Companies usually hire a Head of Payments or bring in an external advisor for setting up payments. Usually costs a few hundred thousand USD/year.
Another good way to make connections is to attend conferences like Sigma, ICE, and iGB Live.