Yes or you save the level5 stages. 0 defends and you loose very often, even with best girls. Round about without special tricks, just normally fight, I get ~80 rounds until cooldown. They are 25/35 really narrow together before the first girl and 60 in the 2nd part. Until then you even may use a cooldown. With 6(7) champions available that are 4/5 and 9 rounds.
regarding the tickets needed:
You should have 10 by autofill, 27 by the free part of Seasons (yes you don't need to take them earlier), around 5-10 per POP per run, can be at best ~30 more tickets per day. +2 tickets per day by daily missions, plus...
At least if you are not just in the beginning. So get up and start leveling and growing your harem.