Is it viable then to develop my own program and assemble a team in order to scout for opportunities on all the exchange sites, as a hand-developed bot would be legit? And since the concept of arb is legit it should work out overall.
The answer is, "maybe."
The problem is because arbitrage is a known concept, but crypto is a fairly new and niche space. With certain markets, especially for new coins, you will definitely be able to make a profit from arbitrage - even probably manually - but when it comes to major exchanges, I'm unsure about the effectiveness of common strategies. You'd have to innovate or get lucky, I think.