It looks like one of them "might" had been shouted out by a much bigger youtuber possibly with million subs and that started that 1 channel and they sort of all 3 shouted out one another periodically sharing the boost the 1 channel got. Some of them include give aways thrown in top of shouting out one another. I don't really watch them, so I don't really know how often they do give aways. My friends that watch them told me they mainly watch them for the give aways. It's also not uncommon for pro streamers to do a lot of give aways also, like computers and stuff.

I think Marvels might be a good example of Smite trending content without give aways and you can see he's not very big on twitch even though I think he's been hosted by pros many times before. He should also be a sub I think for zapmans team, so here you have a guy that should have a good reputation, though it's not benefiting his following that much.

I can tell you though if barraccudda retweets you, you may only get 100 views on the retweeted video. I had noticed a smite video someone sent him he retweeted and saw how many views it got and the guy didn't gain any subs from it either. This is just to imply having a pro retweet you it may not be that beneficial.

So if you are attempting to grow a youtube channel around Smite. Good Luck.

Something I want to tell you. If you only gain 5 subs a day and there is 365 days ina year. 5x365=1825 and if your goal is to get to 100k subs to be able to make youtube a full time job. 100k/1825=52 if that math is correct, it could take you 52 years to get 100k subs. So if you are going to attempt to grow a youtube channel, you might want to aim gain like 400 subs a day.

Otherwise if it takes 52 years, you might not live that long to reach said goal. Of course there's also the factor of not really making any money early on until you reach like 25k subs. Even then some Youtubers who have 100k subs struggle this day and age to get 1k views. If you get around 1k subs, I'll collab with ya if your subs aren't really fake.

So in conclusion, you'll probably need to figure out a game plan to gain a lot of subs early on, or the growth could be so slow that smite might eventually patch or add an anti cheat system that could make it so you can no longer play their game to keep making smite content and then you'll have this small group of smite subs that might not be interested in videos of other games.

In conclusion I think it might be wise to aim to get big sub growth because 1 patch from smite might make the game unplayable for you and then you might have to make content for another game and your current subs might unsub because you no longer make Smite content.