Few things chap my ass quite like people discussing the tang on knives. The size or length doesn't matter that much on a knife sized tool. Only that it's fixed securely. You will almost /never/ break a knife there. If it breaks, it's usually happening at the shoulder where blade and tang meet (if you're using the blade laterally, like a prybar) or the upper half to the tip. (also from using the blade laterally like a prybar)
The tang itself once past the junction of the shoulder is irrelevant. It's not were stress is applied, and your hand+ handle material will absorb much of what's there.
Example of what I mean. Japanese Nata. A woodsplitting tool, not a knife. Short, thin (compared to blade width) hidden tang, but secured strongly with pins.
