You mean 2000 events for 2000 follows? I don't think that is efficient.
Discussion
On the scale of events, think about how many events are created for each unique reaction. Would be orders of magnitude larger than for follow connections. I think a hybrid approach could be tenable where you have a list of all follows to it makes it easy for clients to display follow counts, but the ultimate source of truth are the atomic follows so a client bug can't rug you of all of your contacts.
I think clients will improve and key management will also improve. Browser extensions could detect when a replaceable event changes drastically and ask if that's ok for that kind or specifically handle kind3 or keep backups or ... there is a million possibilities but making the list of follows 5 times heavier is probably the worst approach.