In addition to Mooch's good info, I thought is also worth mentioning that it's been proven time and again (most frequently by Phil Busardo) that some mods simply don't deliver what they claim.
Having blind faith in a regulated mod delivering (hell, even doing) everything they claim it does, can far too frequently fall short on delivering.
In your case, the reason so much caution is being suggested by several folks, is because IF your electronics aren't up to the task, then that load /has the potential to be/ transferred to your batteries. In which case, in series, you'd be at least somewhat safer having guaranteed good 25amp batteries in there.
Unless the mod can actually boost what's being provided by whatever battery(s), then it's all moot anyways. As when you hit whatever wall there is (by design limitations in the electronics circuit), that's all you get. Regardless of what the marketing department says, the engineering department ALWAYS wins. (That's why some single 18650 mods will never hit 75-90 watts as advertised)
And if you are fortunate enough to get what was advertised (and the engineers delivered), then that means a proper boost circuit was implemented. But since you're still working in confined areas (either voltage or current) when one hits a wall, the other has to give. So that means, if you have a hard wall on voltage available (depending on the remaining charge in the battery(s), then the electronics are going to try and make up for it in current. Which is also why batteries have pulse ratings. Because as the voltage* goes down, the "instant surge" (or pulse current) being felt by the batteries becomes even more important.
There's a reason I'm not getting into a math "numbers war" with you, and that's because there's far too many variables at play to even bother to try. But what's more important is that folks understand why certain aspects are what they are, and how it all interacts, so they can at least try and plan for safety. The only reason anyone bothers (myself included) is because we care, and want folks to be as safe as possible! I hope you (and others) get all that I've tried to remind or explain above.
Edit: fekking auto-correct. Lol
changed village* back to voltage like it should have been!