Yea, I quit FKG in part because $300 didn't get me one single top-tier rarity girl. If I recall correctly, even event FKG girls are only 5 stars (though again, it's not like I've played that game in a long time). Armor Blitz meanwhile guarantees you a top tier rare every 28 days for free, as well as every 7500 cores (even before you consider the 1% chance to get a 5-star from pure RNG)

People in mobile Armor Blitz say they got 10-13 out of 15 of their main tanks to be five-stars within only 6 months, for free. Admittingly that probably includes at least 3 event-tanks that were five-stars (so I guess you get 3 events + 6 log-ins + 1 lucky factory draw and that puts you at 10 right there)

...actually, looking at how fast people are filling up their teams, one major issue I think will come up in the future is that you only need 15 tanks. That combined with how every new tank needs to be manually levelled up from level 1 will eventually totally kill the joy of looking forward to getting new tanks.