in my opinion (OPINION), running a single node for Consul Server and Nomad Server should be OK for three worker nodes, keep adequately sized servers, not too large.
Also, the documentation will always recommend separate servers, but that is “high activity” requirement.
How about if you test out the “1 server (consul+nomad) and 3 workers” setup with some production type workloads to see that it works well and as expected?
On a side note, the more concerning thing (if one has to be concerned about) is that fact that you are considering 1 (one) server of Consul+Nomad instead of 3 (three) .
Again, having Consul Server and Nomad Server on the same nodes is pretty OK in my opinion based on your low traffic workload.