for reference.

1 win gives you 32 arena tokens, 5 passes a day is 160 tokens, 7 days a week is 1120 arena tokens.

Diamond 3 (2000 rating) gives 1000 arena tokens Diamond 1 (2300 rating) gives 1200 arena tokens

If you win all the time then it doesn't matter, but if you lose often enough you need to subtract the points lost from the win from the total at the end.

This doesn't take into account the shards you get per win. I've spent about a week pushing into legend and the rewards at the end can increase, since I don't have a lot of experience farming in legend I can't say for certain, but I have myself recieved 2 yellow taex instead of the 1 I get while farming in diamond 3.

TL:DR you can easily keep up with 3v3 farming with no defense in diamond 3.