That's simply not true. Many Russians are swallowing uncritically whatever Putin says. I've personally met on my Elbrus expedition in cca 2016 quite a few in our team (russian agency, I never go with western ones when mountaineering), who seemed otherwise smart, but praised him uncritically like some saint. I couldn't listen to it whenever we switched otherwise normal topics to this.
Not everybody gets their news from internet. And those young folks were from Moscow / St Peterburg and used internet like everybody else.
> are against the idea of Slavs fighting Slavs
Bullshit, army men do what they are told. In 1968 Soviet, mostly russian army invaded Czechoslovakia. Soldiers had no qualms with shooting to ie teenage girls riding across the street on their bicycle, harmless as one can be. Hundreds of cases like this, nobody was armed or posed any threat. Nobody was ever punished, there are tons of memorials across whole country(ies).
There is a lot of wishful thinking in your statement, and I hope its meant in optimistic way. I wish there was really this fabled slavic friendliness since I am also one of those, but I see it more a nice myth which works mostly on language grounds, and falls apart as quickly as problems arise, see ie Yugoslavia.