Let me break down the companion choices since i've spent quite a bit of time experimenting with different options. The boss-type companions like flame tiger and lightning bear are incredibly powerful (this is because they're actually designed as mini-bosses), but capturing them takes some preparation with tranq arrows and careful timing. Something interesting - these companions actually share similar behavior patterns to their hostile versions, which is why they're so effective in combat.

Regular companions you'll find in the wild serve different purposes, and your choice really depends on your playstyle. Pandas create healing zones during fights (which can be a lifesaver during longer battles), while deer and wolves are better for resource gathering and drawing enemy attention. Just remember to keep an eye on their health bars, since they're not invincible despite what some players might tell you.

If you're playing an older version, particularly the empires expansion, the golden panda is worth the effort to unlock (you'll need to invest time in facility development), as it provides some unique tactical advantages. One thing i've noticed is that mixing different companion types throughout your playthrough helps you adapt to various combat situations - sometimes you need raw power, other times support abilities are more valuable.

Remember to carry healing items for your companions, since replacing a fallen one mid-mission can be quite troublesome