I have a '17 Ram 1500 with factory tow package. I think I see what you are talking about.
I just measured my travel trailer's plug, and it is 2" from the face to the latching side of latching lug (like you said). However, on the truck side, the socket measures a little less than 1-7/8" from the surface of the conductor pins to the latching lug latch. In other words, when the plug is latched in the socket there is at least 1/8' of contact 'intercourse'. After coast to coast and border to border trailer towing, this seems to be adequate.
As far as which plug wire goes where; the spring loaded socket cover on the truck has a legend embossed on it that denotes what pin goes to which light.
And, my truck also has a socket for 4-pin flat connector. Unless your trailer has electric brakes, you would probably be more content using a 4-pin mating connector on your trailer (rather than the round 7-pin).
On the 7-pin; as far as "wiggle, push, twist", there isn't a lot of 'feel' when plugging the connectors together. For example, it doesn't 'feel' like plugging your electric drill into the wall socket, or plugging two 4-pin trailer light connectors together. More so, it 'feels' like the plug will just fall out of the socket because it is not firmly 'intercoursed'. Well, when it is latched in place, it doesn't fall out. (But if it is not latched in place it will. Some experienced RVers wrap a strip of velcro around the plug and spring loaded socket cover to provide extra latching security. The concern here is not so much about losing lights as it is about losing brakes.)