I also have been intrigued by this apparent dilemma. I think I have it worked out, maybe only half way. This is all my conjecture, since most people just are not thinking down these lines.
The longer the focal length of the objective lens the narrower the field of view, right? So the longer the focal length, the more the lens is gathering data from a narrower space.. So for best magnification you would want to gather the most data from the smallest area. Thus long focal length.
Now you might also notice that when you use a shorter focal length eyepiece, the field of view is also narrowed. This is because while light beams that are outside of that field of view are still hitting the eyepiece they are being refracted off to useless places if not aberrated altogether with.
So now, lets take for example a 120cm objective, and couple if with a 25mm eyepiece. That is a 48 power telescope. Photons from outer limits of your field of view are coming at your cornea at particularly steep angles. The closer to the limits of the field of view, the sharper the angle it hits your cornea. Beyond that field of view, light beams are still hitting the objective, but are not refracted down to the eyepiece..
Now let's put on a 6mm eyepiece.. Your field of view is now reduced.. What has happened? All the same information is coming down to the eyepiece from the objective. But outside your new field of view the eyepiece is not sending this information to the cornea. It is refracting it or aberrating it too much to be of use.
So let's see what happens when you shorten the objective's focal length. We'll say you have a 120cm Objective and the 6mm eyepiece... With the 6mm eyepiece you are already missing most of the information that the objective is sending the eyepiece... While I can see that I am still missing part of the full conceptual understanding, I don't see using an increased field of view of a shorter lens getting more magnification.
Perhaps magnification is a balance between limiting your field of view with the objective and limiting your field of view with the eyepiece...... Anytime you increase your field of view you are reducing magnification. Decrease field of view, increase magnification. So what you need to do with a telescope is magnify (with the eyepiece) a smaller field of view (from the objective).... I'll be darned, that's what we do......