The sub module name "trace"  under " ../cna-smfcc/1.1.16/trace.yang" is referred under the model " ../cna-smfcc/1.1.16/cna-smf.yang"
similarly the trace sub module under " ../nrf-agent/1.3.0/trace.yang" is referred under the model " ../nrf-agent/1.3.0/nrf-agent.yang"
but when both module yang files are loaded in the reactor & while creating reactor.buildEffective() why it should create submodule collision 

Ref : link kernel-dev