While I think that modern Pagans and polytheists should strive towards solidarity (when feasible) with those who practice pre-Christian faiths and rituals, our support should never be confused with the notion that we have a "right" to "borrow" (and take out of cultural context) their spiritual practices for our own benefit. Empathy for the Indian struggle does not confer the right to appropriate Native traditions and practices. Praying like an Indian doesn't help the Indian preserve their culture and integrity, it only serves our vanity and dilutes authentic practice.There's an excellent article about Responsible Eclecticism and Cultural Appropriation which outlines the difference - basically if you take someone else's ritual and plonk it down in your spiritual context with no thought about what you are doing, that is cultural appropriation. If in addition to that, the group you have borrowed from is in danger of having its culture and land-rights stomped all over by mainstream culture, and you do nothing to help them in their struggle, that is the pits. And most of the plastic shamans have done nothing to assist in the indigenous struggle for self-determination, they've just ripped off their rituals and made a great deal of money out of them.
If on the other hand you look for parallels within your own tradition, and adapt the borrowing to your own context (an example being centering prayer, which is an adaptation of meditation) that is responsible eclecticism.