In meetings and online discussions I've noticed that there are often confident people who dont just believe that they are always right but specifically point that (only) they have holistic (gestalt) view while others are stuck to narrow arguments. They end up with fuzzy "systems thinking" science references etc. Is there a name for this cognitive bias?
There are 2 possible candidates for your question.
llusion of validity, the tendency to overestimate the accuracy of one's judgments, especially when available information is consistent or inter-correlated (Dierkes et al. 2003).
Overconfidence effect, a tendency to have excessive confidence in one's own answers to questions. For example, for certain types of questions, answers that people rate as "99% certain" turn out to be wrong 40% of the time (Hoffrage, 2004).
Dierkes M, Antal AB, Child J, Ikujiro Nonaka (2003). Handbook of Organizational Learning and Knowledge. Oxford University Press. p. 22
Hoffrage U (2004). "Overconfidence". In Rüdiger Pohl (ed.). Cognitive Illusions: a handbook on fallacies and biases in thinking, judgement and memory. Psychology Press.