相关讨论：
- 如何让company-lsp与company-dabbrev-code愉快地工作？
- For a backend group, if the first backend gives candinates, how to discard candinates from the second backend? · Issue #806 · company-mode/company-mode · GitHub
没去认真研究，不知是 lsp 的问题还是 company 的问题。看了一下第 2 个帖子，发现 company 作者至今还没试过 lsp，这俩扩展之间的问题恐怕还得继续存在一段时间：
dgutov commented on Feb 3, 2019
I haven’t tried LSP yet (I hear the Ruby impls are still very alpha), and I don’t write Python. However, LSP completion should include local variables etc. Maybe with some later release of whatever server you’re using.
如果采用 :with 组合两个后端，又不想太多干扰，或许可以自己实现一个过滤器，参考这个帖子《推荐入坑TabNine#40》的回复。