The answer to did the Norse heathens (pagan comes from the greek "pagos" while heathen comes from the Old English "hǣthen" which shares a closer tie to the Old Norse language than Greek) look down at Chrsitians being weakly is both yes and no. Let me explain.

We have in texts where the Norse called Jesus Christ "Hvítakristr" which translates to "White Christ". Now this doesn't refer to his skin color and may have originally been a reference to the white robes Christian converts wore for baptism but the term evolved into a pejorative to indicate effeminacy and weakness (read about ergi and argr to understand the moral values of "manliness" that Norse men were expected to have lest they lose their reputation and legal protections). The use of the pejorative "white" is kind like how they use to say "you yellow liver-ed bastard". In the Icelandic sagas there is animosity between Norse heathens and Christians with the implication of Christians abandoning old ways and championing a weak god. So yes.

But why no too? There was a Christian missionary that acted under Norwegian king Olaf Tryggvasson named Þangbrandr (Þ is pronouced "th" as in "thanks") whom is mentioned in the Icelandic Sagas. In Njal's saga, Þangbrandr is resisted against conversions by many of the people of Iceland with people resisting his efforts. In one instance a man named Þorkell challenged Þangbrandr to a holmgang (a legally set duel) where Þangbrandr fought with a sword in one hand a cross in the other as his "shield". Þangbrandr won the fight and made the emphasise that it was the power of God and Christ that gave him the power. There were many other altercations Þangbrandr got himself into in which he was the champion but his killing streak earned him disfavor in Iceland forcing his exile from Iceland back to Norway where he told Olaf Tryggvasson that he failed his mission and the Icelanders would only mock his message. So why is Þangbrandr important? He is a good representation of the use of violence and strength to create an argument for the "true power" of the religion he came to Iceland to preach. As such he was trying to convert using cultural values of not showing weakness and a willingness to fight to show that in being a Christian he wasn't weak but that also it was his religion that gave him this drive and power and thus in a way saying "your Gods are actually not so powerful". This method of using violence to force conversion was something that Olaf Trygvasson was known for doing which plays into the idea that there was a strategy to convert by changing the nature of a foreign religion to suit a different culture. We can also see this method being utilized with the Anglo-Saxon conversion from Germanic heathenism to Christianity. There is an poem called the "Heliand" ("saviour" in Old English) which describes the death and resurrection of Christ in a format much like that of Beowulf where Jesus is like a warrior that is fighting against death and sin. To get a bigger perspective on this topic read about "Germanized Christianity".

In conclusion there were instances where there were challenges to Christianity being weak but that said there were indeed converts that tried spread the message of Christianity using the language of power and violence if it was needed to be able to guard against themselves and their religion being given the label of weakness and effeminacy. Now to answer the part of reconstructionism, there are beliefs that Scandinvia was primarily converted by the sword's edge which is not entirely true. Violence was by far not the primary method of conversion since there were people that were open to the idea of another deity to add to their pantheon and over time with clergy becoming more prominent in Scandinavia and preaching away the old gods, the gods turned from real to myth. What I also didn't mention was that at the end of Þangbrandr's mission in Iceland and returned to Norway, when he told Olaf Tryggvason about his failure, Gizurr the White Teitsson and Hjalti Skeggjason (whom Þangbrandr had converted) told King Olaf that Þangbrandr's mission failed because he proceeded with violence which is ironic because his only choice in dealing with some of his confrontations was to engage in the language of violence to show that he and his religion were unyielding to the aggression of Norse heathen followers.

Edit: Source: Albert M. Sturtevant, "The Contemptuous Sense of the Old Norse Adjective Hvítr, 'White, Fair'." Preben M Sørenson, "The Unmanly Man: Concepts of Sexual Defamation in Early Northern Society. Studies in Northern Civilization" Laxdæla saga, Njal's saga, Heimskringla (Sagas of the Kings of Norway)