The amount of chaos depends on the startup's finances, those facing financial troubles are really not a nice place to be whereas those that are well-funded are also chaotic, but in a nice way. So another thing to do before joining an early-stage startup is to do a bit of digging to see what their finances look like.
When a startup is having financial troubles and you can afford the gamble (and you've obviously done your homework to see that they're going to get out of that financial trouble), then there's always the option to negotiate for more shares while taking a pay-cut (long-term, this could mean your time investment gets a much bigger pay-out).
Joining a startup that is having financial trouble could mean you don't get paid for several months whereas a well-established company has much less risk of this happening.