Assists don't transfer over from the previous grade for the event? Please explain rito.

So the icon description for the second objective says total assists. I have gotten approximately 50 assists already through the first objective, but when I went up to the second tier, none of my assists transfer over it's kinda annoying cause it says total assists. Also the fact that its 50 assists compared to 20 kills is big discrepancy since you can get 20 kills in even one game relatively easily while getting 50 assists takes at least 2 games at shortest if you are playing a regular duration game or a Aram or Dominion. Now it is possible to get more in a game, however, that would lead to farming assists and I find that to be in bad taste and possibly even against the summoners code.