Kelly , it’s recommended to create a weighted balance rule for all protocols to correctly set the WAN links usage ratio. in this case you can set both weights to 10 but because you have a 2Mbps + 3Mbps it’s better to set the ratio something like 7 / 10. but it’s up to you.
if you set a specific outbound rule for a specific protocol like TCP 1352 , it will only affects on that TCP protocols and doesn’t effect other network traffic like Http , ftp , etc.
if you are creating a specific rule for a specific protocol and also you have created a weighted balance rule for all protocols , you have to put that specific rule on the top using drag & drop facility. because upper rules have higher priority than the lower ones.
from a client pc it sees only the Peplink as peplink is the default gateway, then distributing traffic is the Peplink’s job so you feel higher speed because all WAN links will be used at the same time. if you want to see a good result , I’ll recommend you to create an outbound weighted balance rule as explained.