I can't like those pictures, I just can't.
But look, yes, you need an ohm's meter, *I* need an ohm's meter and I build on regulated mods. I can't tell you how many coils I've shorted out on an ohm's meter, but it's more than the number of my fingers (I have an OHM'S READER, so I still have 10 of them!!!!) It's a great base for building as folks say, and it really.... Steam engine is a tool to approximate, IMO, it's not a tool to be precise with. Not unless you've been winding coils for years, and even then I'm going to bet most mech users or even RTA users fire them and test them on an Ohm's reader first, it's really best honestly, especially as a new user, really, you don't want to have an awful experience due to the lack of a very simple and pretty inexpensive tool that (should) give you peace of mind.
Knowing Ohm's law and steam engine isn't going to make you infallible when it comes to winding coils, I don't think it makes anyone infallible when it comes to coils, not to mention installing them properly on your deck....
Anna