Thanks, this is useful info.
Note that many newer players (like me) depend heavily on renting, in this case there is no problem with upgrading the monsters before the summoners. When you do rent a higher lvl summoner you can then use the upgraded monster as well, so at least one card less to rent. And when you don't rent the higher lvl summoner you can still rent out your higher lvl card. Similarly for the leagues, with my own collection power I would be stuck in bronze, but by renting I can reach silver or gold, get more daily chests and slowly build up my deck. Also sometimes it is even cheaper to rent higher lvl summoner/monster than you are able to play... So it is good to pay attention to the tips you presented with possible adjustments when one relies a lot on renting.
Also there seems to be some issues with the audio, your voice goes down for several seconds a few times (like 6.26, 7.07).
Thanks a lot for your great comment. You are totally right that the situation is different when you rely on renting cards. But still it's important to develop monsters only as much as necessary in respect to the summoner that you are going to rent. It can also be a good idea for example to develop several cards of the same type. For example with reward cards. You make two level 2 cards. You rent one out and you use the other one. Once you develop your deck, you can cancel the rent and merge all the cards together.
I'll need to check my settings. Thanks.
These are good points. I did not know that you can merge developed cards together, thanks :)