For me, unaspected and peregrine are two different terms. If a planet
is both, one has to look at its ruler to determine how it acts. I do,
however, think that except for the ruler's wishes, the planet acts
rather freely. That freedom, however, is probably not so good in most
cases, as it implies a lack of integration.
That an unaspected planet would take over entirely I do not think.
Perhaps in some special cases, but offhand I cannot think of what they
would be.
A planet in its own sign could be said to occupy every degree of the
sign, as it acts through every degree. That makes for more
integration.
If you count modern rulerships, Pluto would not be peregrine in the
second decanate of Cancer. If you do not count modern rulerships, all
the outer planets are peregrine everywhere. I guess one has to take a
stand on how one thinks about those things before one can arrive at
conclusions.
My own take on the modern planets is that they are rather hard to
integrate already from the beginning. They are "generational", etc. I
would also say that is part of how one should interpret them. Pluto in
Cancer, thus, would only be more plutonic, less restrained, less
integrated. But it's already there from the beginning, so the question
is what difference it makes.
/Kjell