Re: 100% utilised redundant links
Basic network monitoring needed here.
Any of these are not hat expensive and would alert you to potential problems like this.
I once had a 1gb link that constantly ran around 99%, we got it upgraded to 10gb which then ran at 50%. Things were a bit quicker after woods. We knew what it was doing due to the solarwinds monitoring we were using.
Besides management like these sort of things because they alert without needing someone sitting constantly monitoring services.