Guideline is not the word you're looking for. A guideline is functionally useless because RPGs require "hard-coded" mechanics to operate. No mechanics, no rules. It would be like saying, "I'm a defender. I protect people, can take punishment and I'm effective in melee." However, if the rules support none of that in game play then you're not a defender. No matter how hard you try. You're like the Mystery Men trying to be super heroes yet never meet the Sphinx.
Well then, what word am I looking for?
Paladins multiclass well with Warlocks because they both use CHA as a primary stat. A defender doesn't HAVE to stand up front. That is a misconception. It's often more effective if they do but they can still be effective when they aren't. Paladins especially.
But then that wouldn't be a defender in the sense of the word, would it? Especially if you mark and then go invis. The enemy cannot locate you, much less attack you, and is thus forced to either do nothing, or attack another PC (at the expense of a lower attack roll and some damage). If anything, you have just given said foe more incentive to want to attack someone else, which seems contrary to your suggested role. The result would be an atypical paladin who can still deal decent damage in combat, but there would be nothing "defender'ish" about him (which we assume is an intentional build design goal).
Clearly you're still new to 4e because everything within your examples is possible and effective. No game can support every design perfectly and maintain a modicum of balance, that's a given. But claiming that a game cannot do what it clearly can only exposes your lack of effort to fully understand the system, nothing more.
I am still fairly unfamiliar with 4e, that much I concede. But I don't get the part where I am purportedly said that the game is unable to achieve so and so. When did I say that?
