it seems in the buddha's time they did not worry about name calling, so vinaya says nothing about it. prince siddhartha gotama became gotama. son (putta) of saree became sareeputta. as already mentioned here, usually the teacher decides the name or the criteria, sometimes the abbot wants all the monks to have a part from his own name eg. "nanda" from the teacher added to "saddha" becomes "saddhananda". this leads to repetitions since limited options.
sometimes some students (perhaps radicals) pick a one for them which inspires them of a certain aspect of the dhamma like "samadhi" or "attadipa". which is good in a way since our parents did it for the first time so when born as monks why not get a name which reminds our goal or a favourite quality. i too like the idea that the bodhinyana monastery in perth, australia, the newcomers get to choose their own.
Power can make things disappear, so does me
Then the Blessed One said to Ven. Ananda, "Now, if it occurs to any of you — 'The teaching has lost its authority; we are without a Teacher' — do not view it in that way. Whatever Dhamma & Vinaya I have pointed out & formulated for you, that will be your Teacher when I am gone.
-Dīgha Nikāya 16, Mahāparinibbāna Sutta
gO tO wORK, gET mARRIED, hAVE sOME kIDS;
wATCH yOUR tV, fOLLOW fASHION, aCT nORMAL;
pAY yOUR tAXES, pAY yOUR bILLS, oBEY tHE lAW;
aND rEPEAT aFTER mE: "i aM fREE."