The concert about the number of MD is from the @tfa idea not yours. Forget to point it out, sorry.
The big problem with your idea is the conversion. If the safecoin price increase, as we expect to happen, the number of small denominations are extremely low and a shortage seems inevitable. This would seriously damage the reputation of the network.
There are other problem and is that the possibility to win in the farming decreases if the number of farmers increases. The ideal is find a solution that suits this possibility. It is what I have tried to do with the activation of decimals in stages.