Reliable Cookie-to-Butter Ratio for Crumb Crusts

I'm trying to find a general and reliable Cookie-to-Butter ratio (or weights) that I can use when I make crumb crusts for no-bake pies.

My old baking textbook, On Baking: A Textbook of Baking & Pastry Fundamentals (Third Edition) by Labensky, Martel & van Damme gives the ratios for a basic crumb crust as follows: 4 parts cookie crumbs to 2 parts sugar to 1 part melted butter. So, for a single 9" deep dish graham cracker pie crust, they recommend going with 8 oz. graham cracker crumbs + 4 ounces sugar + 2 oz. butter (blah, blah…food processor…pressed into the pie plate and baked at 350° F for 10-12 minutes).

OK, I have a few problems with those amounts: (1) 8 oz. of crumbs is WAY too much for a single pie crust (5-6 oz. is plenty), (2) using half as much sugar as crumbs is WAY too much sugar for my taste (I go with more like a quarter), & (3) I can never seem to get a crust to hold together with that amount of butter. Lately I've been going with 6 oz. cookie crumbs + 2 oz. sugar + 2.5 oz. melted butter – I'm pretty sure I can do better than that.

Ignoring my first two complaints – I can get the cookie and sugar amounts right w/o a problem – does anyone have a reliable Cookie-to-Butter ratio that works well for cookie crumb crusts in general? I don't want links to recipes (there are recipes out there with butter ranging from around 15% to nearly 60% of the cookie crumb weight), I want to hear from people who have had repeated success with specific crumb crust formularies (in weights, not volumes).

In a perfect world, I would love to hear of a trustworthy Cookie-to-Butter ratio that applies equally well to most cookie types (I almost never use graham crackers – I'm more of a Nilla Wafer and Animal Cracker kinda guy who dreams of one day branching out into ginger snap territory).