Chat, meetings, and tickets, in that order. Chat is where questions and decisions live day to day, meetings hold the why behind them, and tickets hold the operational record. Three connections cover most of a company's living knowledge.
The principle is highest-signal sources first. Wikis and drives are worth connecting, but they are the written-down subset; the fresh knowledge, what changed this week, what was promised yesterday, lives in conversation.
Every integration respects the source's permissions, so connecting broadly is not a confidentiality decision; what was private stays scoped to its audience.