I know that you only need 9, and the way the fas have been going, you can get the 9th plus another after the fa. The last fa covered two events and had two tomes, both of which gave you a choice between boblin and echos. Didn't someone say that the fas would only offer one artifact or tome now? The next fa will also cove two events. If you miss getting all nine artifacts during both events, you could only evolve one of the event bldgs. Did I read that wrong? Will we get a chance to get missing artifacts for both event bldgs (twilight and flower goblin) or just one?
The next FA will almost certainly have a single 'tome' which will give a choice of 1x artifact for the past 2 buildings, just like the previous FA.
Also, if we can get a better spread of event mini game types, (ie: 1x 3-rotating chest -> 1x 'other' formats), that will make it easier to at least max out the one evo building. Generally the only events where it's super iffy to make the full 9 artifacts is the 3 rotating chests, as you're far too reliant on multiple RNG factors not screwing you over...
With the more 'tactical' event types in the shuffleboard + 'digging mini game' events, as long as you know how to work those events, you'll make 9 artifacts with very few issues.
If we could get the Wildlife mini game from FoE then holy gak, it'll be record breaking how many GP's you can pull out, unless they nerf the hell out of it. (please don't devs, at least give us ONE event that's heavily in the players' favour!!)
As an example, when this new mini game was first put out on the FoE beta server last year, players were
easily gaining 2 fully evolved grand prize buildings, it was that stupid!!
Even with the nerfed version that hit the live servers, as long as you knew what you were doing, it was dead simple to get 1x fully evolved building + a 2nd one half/almost half evolved for 0 diamonds.