What office or status did these individuals hold in Roman-Britain based on their attire?

There is really not much to discern exactly and directly, and unequivocally from the picture as present(ed). That we would see any lictores can be firmly excluded, however, as definitive attributes are missing:

The lictor's main task was to attend as bodyguards to magistrates who held imperium. They carried rods decorated with fasces and, outside the pomerium, with axes that symbolized the power to carry out capital punishment.
[emphasis added, LLC]

— Asset number 34850001: Bronze figurine of a lictor (magistrate's attendant)

A few learned speculations may result in the already mentioned in question decurions or in later evaluations of the available research as:

Possibly also Christian (or at least showing Christians) is the painting of a number of figures from a mausoleum at Poundbury, Dorchester, some of them holding staves or wands. However, the most covincing explanation is that they represent local members of the curial class to which the deceased surely belonged, ‘perhaps specifically those who had held office as duoviri, and assumed a form of dress and insignia appropriate to those in higher authority’.

— Martin Henig: "The Art of Roman Britain", B.T. Batsford: London, 1995.

With Wikipedia explaining:

The duumviri (Latin for "two men"), originally duoviri and also known in English as the duumvirs, were any of various joint magistrates of ancient Rome. Such pairs of magistrates were appointed at various periods of Roman history both in Rome itself and in the colonies and municipia.

This remaining uncertainty allows for a wide range of possible interpretations, of which some are pointing towards the rather low and the very high, with equidistance in explanatory value:

At Poundbury, wall paintings from a fourth-century mausoleum seem to show the older styles with shoulder stripes (Sparey-Green 1993: 135–140; Hartley et al. 2006: 207, no. 193, fig. 37). Though it has been argued that the men depicted might be intended to show the Apostles, their appearance suggests they might be portraits of a family group. Certainly, the very square-cut faces would have been similar to that of one of the burials (Farwell and Molleson 1993: 166). So here we may have a snapshot of some of the men of a later Romano-British family and their clothing.

— H. E. M. Cool: "Clothing and Identity", in: Martin Millett, Louise Revell & Alison Moore (eds): "The Oxford Handbook of Roman Britain", Oxford University Press: Oxford, New York, 2016, pp406–424.

The original excavation report — Farwell, D. E. & Molleson, T. I. (1993). Excavations at Poundbury 1966--80. Volume 2: the cemeteries. is hard to find or access; and itself seems to suffer from its publication value in terms of its own pictures being of degraded quality and printed absurdly small. However, the expert on mausolea Sparey-Green contributing to that volume seems to have delivered almost all there is to say from the sparse and weathered reamins we see today:

I conclude with a strong protest at the total inadequacy of illustration to accompany Green's wholly admirable and learned discussion of the painted decoration – walls and ceiling – from the long-frequented cella memoriae known here as Mausoleum R8(135–9).

Apart from a page of plans (fig.92) showing the disposition of the material within the 6.4 by 4.8 m badly-ruined building, the only illustrations provided are photographed from mounted pages in one of the microfiches, degraded in tonal value and absurdly small: this is a unique thing for Britain and, in one particular, for Roman painting generally. There should have been a full series of colour photographs, including the 'small Chi-Rho', with a water-colour restoration, or at least a black-and-white interpretation. There are, indeed, photographs and drawings, including a colour print, elsewhere (N. Davey and R. Ling, Wall-Paintingin Roman Britain (1982), 106–11, and pl. xl); but since Green is not wholly satisfied with Davey's restorations, that can only be counted as a stop-gap.

The consensus of opinion is that the range of stately figures, brightly dressed and facing east, with a youth in a white tunic with clavi in front, is composed of mortals, lacking as they do the nimbus of sanctity or rank. They are reminiscent of the gaily-dressed notables who greeted St Germanus in 429 (Constantius, Vita Germani, 14 (Sources chrétiennes 112 (1965), 118)). Whether they carried wands, is not stated: here at least three of them do so, and from their black colouring with a white line down their leading edges, we might almost suppose that polished ebony, glancing in the light from the east, was intended. The identity of the figures is very uncertain: there is no known comparison, and no suggestion, for example, that the members of a city ordo carried such wands, although I suppose the decurions may have done so when in office, like the consuls of old. The bouleuterion meeting represented on a bronze coin of Alexandria Troas struck under Gallus (A.D. 251–3) (BMC Troas, Aeolis, and Lesbos, 27, no. 145, pl. vi, 7) shows curiales with no sign of wands. On the whole the late Professor J.M.C. Toynbee's suggestion that ancestors are represented is still the most likely, though proof is to seek. From the reference by Green to traces of architectural detail on other fragments, one is led to wonder whether a Raising of Lazarus may not have been depicted here, on the lines, say, of the fine painting, with Lazarus' tomb shown as an aedicula, in Cubiculum C of the Via Latina catacomb in Rome (A. Ferrua, The Unknown Catacomb (I991), 90, fig. 67). Christ may have been identified by the Chi-Rho; but in the Via Latina scene the onlookers are by no means so individualized as here, and of course carry no wands. Speculation remains; but this brief consideration is enough to show that the report is indeed gravely wanting in point of illustrations of this painting. We are left in amazement that the decoration of the ceiling and walls of this familial tomb should have survived at all.

— George C. Boon: "(Review) Excavations at Poundbury 1966-80. II: The Cemeteries by D. E. Farwell; T. I. Molleson", Britannia, Vol. 26 (1995), pp. 400–402. jstor