Well, that is certainly a possibility - properties of both.
You may be right: it's a reasonable assumption.
The thing is 1/4ƛ GP antennas have been using droopy radials to fix the impedance at the feed point since who flung the chunk. It isn't a recent development, not with this antenna nor the one before it. Unless things have changed with respect to measuring omni antenna types the length of the vertical is what describes it.
On the other hand, not everything fits that profile exactly. There are electrical properties that can speak to this as loudly as the mechanical ones, like some 5/8ƛ antennas that are too short for 5/8ƛ and too long for 1/2ƛ - Maco V5/8 - or have too much length overall to be a 1/2ƛ in the usual mechanical sense - J-poles for example - and, of course, my personal favorite odd antenna out, the diminutive Astroplane.
Perhaps a model of an EFHW with radials overlaying the Merlin would be enlightening.
.50 wave radial effect pdf
Of course, either the EFHW in the above pdf would have to be lowered to the height of the Merlin, or the Merlin raised to the height of the EFHW
