New IRS form 8938

My opinion only. I could be wrong.

Barcrests $4,000 (x3=$12,000) is correct for FBAR. Not food for thought, an FBAR must be filed.

For MFS, resident abroad, there are 2 thresholds for 8938.
"the total value of your specified foreign financial assets is more than $200,000 on the last day of the tax year or more than $300,000 at any time during the tax year."

Note, it says 'total value'. It doesn't specify if this is the day to day sum value or an aggregate value. The $300,000 during the year reduced to $200,000 on the last day of the year, may indicate the $300,000 is a day to day sum (aggregated???). Barcrests accountant may be protecting against a worst case scenario. A wise move. As far as I know, there are no penalties for over reporting if the filer sincerely believes that's what is requested. Not reported, or underreported: there be dragons.

FBAR reporting, and one assumes 8938 reporting, concerns primarily the reporting of the actual accounts. The amount of the account, for FBAR at least, is secondary to the need to report the account. For 8938, Part IV comes into play. It's only when the account has been noted (or not), do the amounts come into play. If it hasn't been reported, or is underreported, penalties can commence.

To complete Part III of 8938, it requires the use of 2 pages for each account if filing a paper return.

Just my opinion... aren't we being unnecessarily complicated?

The "total value" of the assets at the end of the year means add up the value of each account/asset and see if the total value exceeds the relevant threshold. Barcrest's $4,000 can only be in one place at that point, so only gets counted once.
(I realise that knowing what to include and valuing some assets may be a problem).

Once it is determined that 8938s have to be completed, the requirement in Line 4 is to report the maximum value of each account in the year (just like FBAR). For this purpose the $4,000 may well be counted several times if it has moved around between accounts.