Not really.
Recording on the Zaxcom TRX is all well and good but if there is a powering issue on the TRX or a bad audio cable, your hop will be down, and so will your back up.
I would go SRa and 2 LMA's, use the money saved (if any) to buy 2 SB-3's to keep everything in sync and roll your backup on the 552. Monitoring a wireless return is pointless IMO, you don't know where in the chain the drop outs are happening, it adds another channel of wireless to the mix, and if your backup is rolling with TC ref, you are pretty well covered even in the unlikely event of there being an issue with the hop. Just make sure everything is properly set up at the start of the day and check it periodically and you will be fine 99.9% of the time.
In future when you don't need a hop, the SRa and transmitters can be repurposed as talent RF's. SB-3's are very useful to have in your kit too, and will easily pay for themselves over the years.