We often work concurrently/individually with multiple small projects, which incrementally build on a large set of enterprise applications. Each project usually lasts 3-4wks from devel to test to deploy.
Is there a described approach or paradigm towards this scenario that can help promote the virtues of agile/lean?
Your approach may already be pretty lean as you describe frequent delivery of small increments of capabilities.
To look more deeply, look at the subtitle, " - From Concept to Cash" A lean approach will work to minimize Cycle Time from when a capability is requested to when it is in production. If things sit in a big queue waiting for you to get started to them or if there is a long integration, testing and deployment process after you complete "your part" then you have opportunities to get much better.
Similarly, if you are working on many small projects at the same time, then you would probably be taking more time than necessary to deliver each one. The critical measure is elapsed time, not applied time. The focus is on the throughput of delivered benefit (cash flow), not on utilization of applied people.