Gothic/Frankish sources for Middle-earth words?

[Tuor of Gondolin]

Upon first reading LOTR I was struck by Peregrin Took's
nickname, and wondered if it was a conscious or subconscious
allusion to some of Charlemagne's ancestors. Then in
Carpenter's Bio he notes Tolkien's interest in Gothic being
whetted upon buying Joe Wright's "Primer of the Gothic
Language." In historical context, Pippin I and Pippin II
were mayors of the Palace in Austrasia and Charles Martel
"The Hammer", who turned back the Moors was Pippin II's
son. And Charles Martel's son, Pippin III, was also known
as Pippin the Short. Pippin III was Charlemagne's father.

Given Tolkien's use of Norse mythology for dwarf names and
Gandalf, is there a similar pattern in place and person names
in, say, Rohan?

However, in the same magazine article in which questions about the
name Pippin were reawakened (Military Heritage,
June, 2005, p. 68 ) there is a comment which would seem to
indicate that Frankish cavalry was not especially talented, and so
might not be the source for Tolkien for the Rohirrim:

Charlemagne also learned from his enemies. Although he managed to defeat the less disciplined Lombard and Avars fairly easily, he recognized their innate superiority as horsemen and soon put them to use in his own way.

(Somewhat reminiscent of the way Denethor hoped to use the Rohirrim
against Sauron just before the Battle of the Pelennor Fields).

Oh, and is Meriadoc of Frankish origin? (As may be obvious, I'm
no linguist or philologist. But, as Cliff Claven once observed in an episode
of Cheers: "Hey, inquiring minds want to know."