With this addition, it may very well effectively make Members feel less exclusive on Forums; more-so than they may already feel. At the end of the day, a Member really only has the ability to 'vouch' for those who wish to have a stronger influence in the clan/community than an xG-Representative. Take that away, and there will literally be nothing special about being a Member aside from having the ability to apply for a Staff Position.
Also, as you previously mentioned, this'll also require Members who are heavily unbiased since they'll have the power to grant or deny Membership which is incredibly difficult to find around here. The role in itself is a very powerful responsibility to have as well.
Annihilating the need to actively seek the approval of others may also diminish the whole reason behind it; making acquaintances or friends with Members of XenoGamers. Without that, they won't feel the need to approach anyone and may therefore be accepted into an otherwise unfamiliar and unfriendly clan.
I see the whole central idea around this, making the whole Membership process cleaner and more efficient, but I just can't see the pros outweighing the cons for this particular suggestion. Mind you, I've only brought up "what if" claims but they are sound and are likely to happen should those changes be made.
Rather than introducing a new system, I would suggest a revision of our current guidelines for Membership. As of right now, there are a lot of things wrong with it (the fact that we have segregated #s of vouches required for each Division is messy and clunky is just one of them) and it would be much easier to build on what we already have going for us. By all means it won't be something that would be done over night. It will require proper discussion, compromises and the like from all of the Higher-Ups (including the CLs) to reach an agreement. That being said, it will also require some effort from Members. It's getting dragged out more than it needs to be, but it's still very relevant that Members review their vouches before they post them. If change is to be had, then the Players/Members/HigherUps have to be just as responsible to assist and support those changes.
TL;DR - Pros outweigh the cons; this would just be an addition to cover people's asses who have a responsibility to properly do what they signed up for in the positions they are in whether that be Member or Staff, which is not the way to go about things.