I just tried your suggestion. Here's what I found and think.

It's [u]unnecessarily awkward[/u], and not because I'm unaccustomed to it. I can and do adapt to alternate fingerings very quickly where there's purpose or advantage to doing so. More importantly [u]for me[/u] in this case, for my handspan and notably [u]length, shape and flexibility[/u] of [u]my fingers[/u] it's a FAIL.

Other than leaving the forefinger free for a rapid transition to a barre anything, pragmatically as opposed your hypothesis, it doesn't offer any actual material advantage switching to/from Am or C and thus reason to deploy it, nor is it facilitative for standard progressions in which those four chords commonly occur. You'll also have less power, speed and overall dexterity aka control with your pinky with any chord regardless how well trained. Just how it is.

Another consideration is that the conventional fingering of D facilitates an anchor finger for rapid A-D-E and variations thereof transition using the alternative fingering of A.

All that said, [u]if it works for you...why not?[/u] However, even if you prefer and pursue it, like G and A, I'd work in the conventionally taught D form first, and once instinctively competent with it, add the alternatives to your 'toolbox'.

As you progress, you'll discover alternative fingerings for the same chord voicings for many chords with anchors and positioning optimally facilitative to whatever it is you're playing, adding them to your chord repertoire and alternating between them subconsciously as suits.

For instance, presenting a case for conventionally taught first form D, watch this. Add pinky for for D sus4, D sus2, D6, D add4 and as previously mentioned anchor finger in position for D-A-E transitions as apparent.

Just my observations and thoughts. Christopher and those more advanced than me may offer an alternative perspective ot be able to provide insight of which I'm yet unaware.

All the best,

manXcat