The observations about instrument position have merit. It is very wise to arrange the instruments as closely as possible to the FAR Part 23 standard quoted. All certified aircraft made since the mid '70's will have this arrangement, to the extent that they are equipped.
The reasoning being that the pilot will develop muscle memory for the instrument scan, and instinctively look to the correct position on the panel for the information they seek. This becomes more important for night flying.
The other thing I do when making or approving instrument panel changes is to insist that the panel itself be any colour other than black. The reasoning for this is that the eye is more able to distinguish any particular instrument because the black round face is contrast to the not black panel, and the eye can center on the instrument, and perceive the information rapidly. In the case of a black panel, the white marks, numbers, and pointers can become a blur, particularly if the instruments are very closely spaced, or of poor arrangement. This can make night IFR flying quickly tiring. It is perhaps for this reason that some black panel aircraft have a white or yellow line painted around the central instruments.
The "glass cockpit" displays will of course cause the need to rearrange things, and new standards for arrangement. But any attempt to maintain consistency of the steam gauges which are installed will be worthwhile to pilot perception, and ease of transition from type to type.