When a team falls into negative numbers and has to pay 5% until they are back to positive numbers actually what happens is that the game "borrows" this team the money it has in negative and for this reason charges it a fee of interest.
There could be a table in which the most solvent equipment of the least solvent is classified and on the basis of this table it is applied a greater interest to the least solvent equipment, and a less interest to the most solvent or safe equipment, as happens in real life
The risk of the team going bankrupt and not beingable to finish paying the loan would exist, but it would be off set by a higher interest
I don't think this wouldmake the game easier, but it would make it harder as smaller teams could develop faster and the most important teams would have greater threats to their development and should continue to improve
It would also solve the problem of the game of teams that accumulate large sums of money, because in this way it is in their interest to lend the money rather than keep it in storage