[GNC] Is it reasonable to have sub-accounts under Equity:Fixed Assets?

[Dr. David Kirkby]

Apologies if this is too much an accounting question, but I'm stuck, and am
trying to work out how GnuCash will handle this.

I'm trying to enter into GnuCash my company accounts for this financial
year only - I'm not going to bother trying to enter every transaction since
the company started. So the opening balances should reflect the company's
financial position on 28/2/2022, and transactions from 1/3/22 being
recorded.

I have the account

Assets:Fixed Assets

All that contains is test equipment and computer equipment, all of which
will be depreciated - there's no land, or other things that don't
depreciate.

I initially set Assets:Fixed Assets to have an opening balance of £x, as
that's what my accountant told me the total of all thef fixed assets was
worth. I see that is reflected in the account

Equity:Opening Balances

However, after I asked him, my accountant gave me a breakdown of the net
value of the individual fixed assets, which have obviously depreciated over
time.  I thought it would be useful to have their individual net values on
28/2/2022 recorded in GnuCash, so when I depreciate them next year, I can
keep a track of the depreciation. (I also thought of depreciating them
monthly, which I could probably do with the scheduled transactions, as my
accountant is using linear depreciation).

That brings me to the problem that my initial entry for the opening
balance of these fixed assets would be wrong, and should possibly set to
zero.

Can I set that balance to zero, then delete the appropriate Equity:Opening
Balances entry?
Would it be sensible to have a sub-account under  Equity:Fixed Assets, or
is that just not sensible?

Obviously by the very nature of a double-entry system, in order to debit
the Fixed Assets, I need to credit somewhere else.