Overhead Hangs vs Edge Lifting Performance?

The past month or so I've been experimenting with edge lifts for finger training as opposed to the overhead hangs that I historically do and have noticed some odd results.  Despite the fact that my fingers seem to be about as strong as they were a year ago, (hanging the same weight overhead on the same edge) they're about 10-20% weaker when I do one arm lifts as opposed to two arm overhead hangs.  

Caveman math would indicate that the sum of what I can hang in each hand should be fairly close to what the two hands can do working together, but I'm finding that isn't the case.  Their powers combined seem to be more than when divided.  Factors I'm guessing play a role: 

• years and years of familiarity with trying really hard while actually hanging vs relatively little experience doing so lifting.
• one hand is likely stronger than the other. (but testing would indicate not enough to make up the difference)
• In this case edge profile can't take much credit because the edges I'm using for the lifts are objectively better than the one I've been hanging from.

Curious to hear if anyone has further insight into this?  Also, side-note, when training two hands/arms of different strengths, is it best to train each at the same resistance (defer to the weaker arm in hopes it someday catches up to the stronger) or to train the weaker at lower resistance and the stronger at higher resistance?

Tyler has done some research on this (and also just passed along other info he gathered from studies I think), that shows that some of the load gets transferred to connective tissue along the chain, in "passive tension" (whatever that means), and doesn't concentrate the load to the flexor tendons that are more isolated in an off the ground pull.

This reasoning is part of why OTG style finger work has become more popular, and likely gets more targeted stimulus to the tissue.  I mostly do it cause it's way more comfortable for my back and hips though.

I'm sure with a little googling you can find the podcast I heard that in, but I'm pretty sure it was an old nugget

I don’t think it matters if you go with a lighter weight when working a bilateral deficit as long as you get close or achieve failure. But you’ll likely need to do less reps. Unless it’s a really significant difference in which case you could drop the weight for the weaker side. 

I’ve done overcoming iso pulls from the ground on a fixed tension block but haven’t used weights. I’m sure it’s useful and clearly activates a bit more “squeeze” in the fingers than yielding isos on a board. And great for noticing and fixing bilateral (edit: sorry I mean Unilateral) weakness. Just takes more time to set up/take down. Regardless of method I’d remember that consistency is probably the most important aspect of training fingers regardless of method. Get close to failure by any means and do that for years! haha  

That said another benefit is ease of scaling up weight and tracking progress OTG. It is a more active pull OTG but i find I get more benefit from old fashioned repeaters on a board. I find the curl up kinda awkward for some reason. 

Just keep in mind that tendon takes 12 weeks to fully remodel so I’d be slow when adding weight in that time frame  

Have a look at the 'bilateral deficit' - because you have more neural drive available with one limb you should be able to do more than 50% of your 2 arm hang.

However, you might be able to apply more passive tension hanging as opposed to lifting?