Wrench and spanner are the same engineering and mechanic tool. Wrench is what is used outside North America (Canada, United States, and Central America) and Spanner is used everywhere else in the world. They’re basically the same tool just are referred to with different names by different parts of the world. That’s a pretty common thing.
As far as costs to craft the power coils, I do think it’s a bit silly to have to make upwards to 24 of them to hit max Power on your machine with Advanced Power Coils (which is something like 7000+)…
It’s the main reason I haven’t bothered to even craft them to begin with because they’re so expensive to make. I don’t even have T1 Power Coils cause they’re a waste of time in the game’s current economy. I rather just drop 100k coin on Advanced Power Coils that someone else has crafted per Machine I need them for instead of bashing my head against my computer table just to gather up the Ancient Techs needed or any of the other rare resources required.
I honestly would rather see 1 to 4 Power Coils needed per machine than having to craft a couple dozen and end up having a massive workshop for no reason cause having multiple Machines is ideal.