Multi-Source power?

Hello all, i'm thinking on a very easy way to support more than 1 power source for my electronic circuits.

Below you can see the schematic. It's very basic. Each source have a rectifier diode to disallow inverse currents for each one.

When both sources have the same output, both diodes will work and the output is Vin - 0.7
When one of them is bigger than the other (the case on the schematic), diode on smaller source will open circuit, and the bigger is the one to be used. The output will be 7-0.7 = 6.3V.

The problem i found is when there is little difference, this is less than 0.7V.
This way both diodes will work but there is a difference on voltage between the two sources.

Do you think that having a small resistance like 10Ohm and high dissipation in one line will solve this?

Do you think this design is valid?

thanks for the help in advance.

Picture of Multi-Source power?