Compare Signal Strength from an iPad vs. Mobile Hotspot, such as Nighthawk

Has anyone compared signal strength of using my iPad Pro(Gen 5) as a hotspot vs. something like a dedicated Hotspot, such as the Nighthawk M6.   I am not worried about the number of users, but instead the signal strength for just me as I want to get better coverage.

NOTE:  I am referring to the signal strength of the "radio" from device to the cell tower.   This could be a combination of both the antenna strength and regulatory limitations that might exist.  

As a further comparison, I believe that your handset (i.e., iPhone) is limited to the strength based on health and radiation as it relates to being held close to your head.   I am wondering if the iPad has that same strength, and likewise the same for a Hotspot.