Your interpretation of Jesus' use of the mustard seed is in error because he is teaching the seed is the least DESIRABLE among plants yet outproduces all others even in the most harsh of climates. The Mid-eastern mustard specie as would have been known to him is a very prolific reproducer.
"In 1976 Indian farmers plowed the ground then broadcast the seeds by hand, others used seed drills. By sowing 2 kgs. per hectare they were getting an average yield of 547 kgs per hectare. Record wheat harvests in the US sometimes exceeded 100 bushels per acre, and most of the highest yields were probably in the range of 125-150 bushels per acre with few reports of higher yields. Standard wheat sowing rates were usually 1-1.5 bushels per acre. A species of brown mustard produced on average more than 250 times what was sown in India with the world record not known."
Jesus is teaching that if we had the faith of even one of the least desirable mustard seeds, it would grow and outproduce beyond our wildest imaginations.
Regards,
Both well reasoned replies. Thanks.