Chana tarakari bro, your comment shows how ignorant you are.

First of all you take that all the brahmins who decide to put Sharma as last name will also add their specific last name too. Say Rajendra Neupane, according to you he will only put it as Rajendra Sharma Neupane. Not true, he might put it as only Rajendra Sharma. Similarly many Newar brahmin (Rajyopadhya) has began to take Sharma as last name.

Then you give me example of why not Maharjan Shrestha, Tamrakar Shrestha, Sthapit Shrestha and Shahi Shrestha. If you are a Newar or know about Newar, you should know that they are not entitled to take Shrestha as a last name. As Maharjan/Shahi falls into lower tier in Newar social strata and remaining two are buddhist Newar. Only Sishya category of Newar can take shrestha as last name but basically it has been a choice of mostly panchthare newars. But getting back to your compund last names recently adding shrestha after specific family name has began to appear mostly in intercast marriage, for example Hari Thapa Shrestha.

You also talk about there being no demarcation of bahun, chhetri and baisya in Newar. There is clear demarcation on some and there is thin on some. For example Rajyopadhya are clear Brahmin and marry within Rajyopadhya only. While Karmacharya, Joshi are taken as brahmin of lower strata than Rajyopadhya and they do marry with other higher newar caste. Jha and Mishra are also brahmin in Newar community for lower tier newars.

Now talking about Chhatriyas in newar, Malla, Pradhanang, Thakojuu (Tahkuri Kings), Patrabansha (Mahapatras), Mool, Malla, Amatya, Pradhan, Rajbhandari, Hada, Maskey, Pradhanang are clear Chattriyas of Newar community. Most of them originating from previous royalties or bharos (bharos is bhardar of early Malla and lichhawi timees)

Chana Tarakari, you also talk about failure of Jaya Sthiti Mallas of social demarcation. You are wrong. Newar is one of the most conservative society in Nepal and has followed the social norms established by Sthiti Malla very strongly. Like Saurav has pointed, anybody who came to Valley after the Sthiti malla was put in lower social strata (example: Nagarkoti) and anybody who married to outside to Newar were outcasted to mothers class. Where in case of other like in parbate, they are more liberal, and put into khatri, jaisi etc be still in part of parbate community. But in Newar, if a newar man marries a Gurung, their children is made Gurung and hence none newar. That was how the tradition was.

You also mention on one hand that most of the Shrestha are farmers, that is not true. Original Shresthas are not supposed to do farming, speically in the Kathmandu valley. Remember the newari cast devision was strictly based on labour and only jyapus were supposed to farm. There might be two reasons why the chanatrakari have seen shrestha doing the farming - one by economy hardship and another he may have seen the rich maharjans, suwals, duwals, tandukar etc jyapu taking Shrestha surname to rise the social status.

Yes, you will see most of newars doing the business? Why? the answer is clear why will Shahas (conquerers) will recruit the Newar in the Army and keep themselves in the danger. And Divya Narayan Shrestha clearly mentioned the danger of it in his Divaupadesh. So there has been only few Newars taken into Army. In whole Shaha dynasty after fall of Malla you will come across only 3 names of prominent Newar bhardar and all three times major thing happend. King Rana Bahadur shah was killed in Kaji Tribhuban Pradhan's house. Gagan Singh Rajbhandari's murder caused the kotparba and Colonel Uttar Dhor Rajbhandari was one of the mastermind of Bhandarkhal parba.

You have also cited Satya Mohan Joshi as Shrestha coming from Shresthi  of lichhawi times (which might be the origin of Seth or Mahaseth of  Baishya caste in India). That might have some relation to business class Shisyas.

But lets get back to original question: "According to one Nepali Historian, there was Zero number of people who had 'Shrestha' as their last name". That is right, If you dig into history you will not see Shrestha mentioned in the past. You talk about Jayasthimalla, Do you see any Shrestha class mentioned in jaya sthiti malla ko jati byabastha? I doubt there is but I can not confirm as I do not have that book with me. (Jayasthiti Mall ko jati byabastha by former Chanceller of TU. Dr. Chandra Prasad Gorakhali).

The most influential factor in rise of Shrestha number is because of  newars of lower social strata like dali, namarmi, jyapus, kashai, malalakar, ranjit, chitrakar etc taking the shrestha last name to raise their social status. That is a dumb as many of the lower newar castes were higher castes or royalties in the past. For example: Kashais are the descendants of Mahishpal Abhirs and Gopalis were the gopal kings. According to Dr. Jagdish Chandra Regmi, most of the Jyapus are from licchawis. According to Bashu Pasha, Malis/Malakars (Gathus) are the descendants of Kirati kings, According to Bhakti Das Shrestha/Rajendra Shrestha Manandhars have some greek blood and came from Shalmiya country of west india. Even when you look at facial feature of  lower class newars they look more aryan than other higher class newars - for example Kashai, chyame, dhobi etc.

Caste is what but the power. We have seen Magers converting to Kunwar and then uplifting to Rana and then proclaiming themselves to of rajput dynasty. Was it long ago that KC's or khatris were made chettris by Bir Sumsher and Nakarmis to pani chalne from Sudra. And offcourse look at the fall of the legacy of Newars - who once had Biggest Nepal from Assam to Kashmir  (much bigger than before sugauli ko sandhi)  and who were taken as proudly by Chandragupt Maurya and SamundraGupta Maurya for bravery from braveness to coward by the Khas conquerers who had most hard time even winning the tiny Kirtipur and had to take helpof lies and trickery to win.

Now getting back to letsplaygolf
There was a ridiculos, illogical comment by Letsplaygolf about pradhan associating with Dhan. Pradhan is one of the highest tier of Newar social class. Any body carrying dhan will not have been put in such rank by pure south indian conservative brahmin like Lambakurna bhatta into higher social strata who can marry to royal kings.