Q:
Engi or Ranger...Arenas.
Roll both!
All in all I think ranger seems more to your liking. As characters they can be far more varied than engineers. Ranger is very fun in and can be very effective in TPvP (if you want any builds let me know what type). Like I said at the start you can always roll both, but it seems to me you would like Ranger to start. That said, both classes are great and I am sure you will be happy with whatever you pick.
Source: Has and engineer and ranger
Ranger was my first main. It was so boring that it literally made me quit the game and go back to wow for a couple of months. Its so much worse than hunter in wow tbh.
I rerolled engineer when i came back and played 2500 hours since. A lot more depth and diversity.
So, I won’t outright say x is better than y here, because it is a matter of opinion to a degree. But I will say engineer is currently in a better spot than ranger in PvP. Ranger is easier to learn, however, and has arguably better contribution in most team fights. However, as you’ve noticed, an engineer who is built for it can easily hold off a 2v1, and win many times if the opponents are of lower skill. The downside is they take a bit more to learn, but once you’re a good engy, you are one of the strongest classes in the game.
Engineer also has more low-end competitive builds (you’ll only see a few variations in major tourneys, but you can play a lot of things in tPvP and do well). Vee Wee’s channel has a few good builds to start with, but I would say play with things on both classes if you can. Find out which is more fun to you, and stick with it.
TL;DR: I prefer engineer, both can be fun.