Do you mean deploying the pair Aruba 5400R zl2 as a VSF or just using two standalone Switches?
I saw some Validated Reference Designs (one is here) using two Aruba 8320 (I think not deployed as a VSX...which is somewhat strange IMHO) along with two Aruba 3810M for management...it could be overkill (especially using Aruba 3810M just for management and not using VSX on ToR Aruba 8320). Another interesting guide is this one. you will notice how ethernet portions (the isolated ethernet network - for iSCSI over 10Gbps interfaces - placed between VMware Hosts and HPE MSA and ethernet network - for frontend connectivity - placed between VMware hosts and its clients) are implemented without indicating a particular switch series (nor brand)...the focus was on the Fibre Channel side on that guide. You can use also HPE FlexNetwork (with deep buffers for iSCSI!) switch on the VMware Hosts <--> MSA portion...of any other deep buffer switch series...I'm not totally sure that positioning there two modular Aruba 5400R zl2 will be wise...better two Aruba 3810M (if Aruba 8320s are out-of-budget). The frontend net could instead a good place for Aruba 5400R zl2...but you should also consider new series like Aruba 6300F/6300M and 6400M recently presented.