This might actually work.
There could be an option to choose between x3 sm earned or like 1 token every 5 wins.
That way sm grinders can get enough of the sm they need.
For the people like me, who really can't improve their mech that much but still might need one or two more items, we can grind wins and evenually get tokens to buy a gold or silver box.
If anyone thinks that 5 wins = 1 token is too easy to get, the work needed to get a token could be raised, say, every 5 win streak or every 10 wins or 10 win streak.
Thanks, ~Maxx