You can't see overlap in a flat list of 40 tools. You can see it instantly when those tools are grouped by what they do. A simple category map is the most useful artifact in any stack review.
The core categories
- Productivity & collaboration — email, docs, chat, meetings.
- CRM & revenue — pipeline, marketing, customer success.
- Finance & operations — accounting, billing, procurement, payroll.
- Data & analytics — warehouse, BI, dashboards.
- Engineering & infrastructure — cloud, code, monitoring.
- Security & identity — SSO, endpoint, compliance.
- Vertical & point tools — anything specific to your business.
Use it to spot three things
Overlap (two tools in one box), gaps (an empty box that matters), and concentration (one vendor spanning many boxes). Each tells you something different about cost, risk, and resilience.
This taxonomy underpins the Technology Physical's redundancy analysis — categorization is what turns a tool list into a decision.