S.T.A.L.K.E.R: Call of Prypiat

I will describe how I got the trophy based on my own experience. I had to run the game three times because the information was scattered and there were some rather non-obvious nuances. In the first run, I did ALL the game's quests, but did not get the trophy. In the second run, I completed the main ones for the Stalkers (Beard's Quests, Hunters' Quests, Mityai's Quest, Vano's Quest, Magpie's Quest) - the trophy also did not drop. In the third run, I did not even do half of the above - the trophy dropped. So, in order:

1) First of all, I did Boroda's quests "Deal" and "Run" , one of the tips correctly indicated that if you do these tasks not for solo players, then the trophy will not drop at all. Also in these quests it is VERY IMPORTANT to make sure that the stalker Spartak does not die in the process of completing them. He was my stumbling block.

2) Then I completed the quests "The Lair of the Bloodsuckers" and "The Disappearance of the Stalkers".

3) After the quest "Disappearance of Stalkers" the opportunity to kill the chimera on Zaton opens. We kill the Chimera, and along the way we kill the Controller in a dangerous cave. We take the quest from Sych to work with scientists (search for three Veles) and go to Yanov.

4) On Yanov, I initially reported to Zveroboy about the Chimera on the backwater and took the quest for the bloodsuckers (Swamp creatures). Then I immediately took Vano's quests and the quest to save Mityai. First of all, I went to Kopachi, took the second Veles detector (the first one is given by Boroda for destroying the Bloodsuckers' lair), then I dropped by for Mityai, took the Heart of the Oasis, paid Vano's debt, went to the scientists, gave the heart, received the third Veles and gave it to Novikov.

5) Returning to the station, I reported on the quest to Mityai and Vano, and while Flint was talking about how he visited the Oasis, the trophy dropped.

That is, I didn’t even complete half of the supposedly required quests. I didn't officially find Soroka, didn't do Shchepka's "Retribution" quest (which is listed on Wikipedia as essential for the "Friend of Stalkers" trophy), didn't do any of Zveroboy's quests, and also didn't do Sych's "Business with Scientists" quest, and, accordingly, didn't do the quest for the Compass for the Beard. It's hard for me to say what the fundamental difference is between this run and the previous two, but since I didn't pay attention to whether Spartak survived in the first two runs, I can say with confidence that the third run was DEFINITELY different from the first two in one thing - I destroyed the bloodsuckers' lair with gas. In the first two runs, I used the electrical panel, which I jumped on, shot them right away and immediately completed the quest. As I understand it, it simply didn't have time to "activate correctly" and immediately surrendered to me, which may have broken the achievement branch. I can't say for sure, but I highly recommend that you pay attention to these two points: Spartacus' survival in the quests "Run" and "Deal" and destroy the bloodsuckers' lair as the developers intended.

You need to complete almost all quests from neutral stalkers