LLOEG(Y)R: FROM LATIN LAICORUM?

A couple different theories have been proposed for the etymology of the Welsh name for England, viz. Lloeg(y)r.

From the Wikipedia article on the place-name:

"The exact origin of the word is still a matter of speculation. 12th century AD author Geoffrey of Monmouth offered a fanciful etymology in his Historia Regum Britanniae, deriving the names of Cambria, Loegria, and Albany from the sons of the fictional Brutus of Troy: Camber, Locrinus, and Albanactus, respectively, and makes them the eponymous kings of Wales/Cambria (Camber), England/Loegria (Locrinus), and Scotland/Albany (Albanactus). In 1982, noted linguist Eric Hamp suggested that Lloeg(y)r could be derived from a Proto-Celtic compound *(p)les-okri-s, meaning 'having a nearby border, being from near the border'. Ranko Matasović prefers to see Lloegr as coming from a Brittonic collective noun *Lāikor meaning "Warriors", the root of which he proposes gave Old Irish láech "warrior" (though some scholars regard the Old Irish word as a loan from Latin laicus, "laity", "of the people"), from a Proto-Indo-European root *leh2- "war". The suffix -wys found in numerous Welsh folk names, including Lloegrwys, is derived from the Latin suffix -ēnsēs.

It seems to me we can simplify this considerably. Why not see Lloeg(y)r as merely a straight-across borrowing from the Latin genitive plural laicorum (m.)/laicarum (f.)/laicorum (n.), from laicus, “of or belonging to the people or laity, not priestly, not consecrated”?  As is typical of Latin words that go over into Welsh, the -um suffix would be dropped, leaving "laicor."

If this name were used for England, it is probably a tacit acknowledgment that at least until the Saxons took over the country was still predominantly Romanized.  A lay person was a Christian who had not been trained or ordained as a priest.  But he could be clearly distinguished from a pagan.

Number	Singular				Plural
Case / Gender	Masculine	Feminine	Neuter		Masculine	Feminine	Neuter
nominative	lāicus	lāica	lāicum		lāicī	lāicae	lāica
genitive	lāicī	lāicae	lāicī		lāicōrum	lāicārum	lāicōrum
dative	lāicō		lāicō		lāicīs
accusative	lāicum	lāicam	lāicum		lāicōs	lāicās	lāica
ablative	lāicō	lāicā	lāicō		lāicīs
vocative	lāice	lāica	lāicum		lāicī	lāicae	lāica