"Shield designers. " Topic

What kind of shield designs would you see on newly raised foot seargents / soldiers and mounted sgts that have no prior employment or allegence to a particular noble. Thinking Lion Rampart soldiers mtd and foot newly raised for a retinue that would not nessesarily have the lords livery? Any help would be appreciated. Would these "tavern sweeps" have their own kit and have individual-whatever colors (colours) on shield fronts? Or do we even have a clue?

Medieval England and Scotland – this may not be case for other countries – …everybody provided their own kit. Gentry and upwards will have their own devices and anyone else paints their shield as they fancy.
Allegiance to a lord is not significant for the infantry; they get recruited by the local sheriff. Conflict between lords is pretty rare and seldom involves infantry at all other than guarding castles.
Most MAA serve the crown directly; even really major lords seldom have a knight service obligation of any great number and those who serve have their own devices; they don't wear that of another person.
Tavern Sweeps – I'm guessing that that is what it sounds like? – and unarmoured riff-raff don't really feature in medieval wars in England and Scotland, but figure manufactures like them, so they make them. Consider this – in 60+ years of more-or-less continual war between the 2 kingdoms, most years did not see a field army being raised at all, just the hiring of MAA for operations and paying very small numbers of infantry to guard their bases (castles).
The sort of 'big medieval army made small' approach of rule-writers does n't really reflect the nature of medial war at all I'm afraid – or at least not in England or Scotland; things may well have been different in Spain or Italy for all I know. In Eng & Sco it's almost exclusively about the MAA..also, a 'dismounted MAA' as per Lion Rampant just means a MAA who is not currently sitting on his horse, it's not a troop-type.
Bear in mind that Lion Rampant is not really a middle ages game, it's an adventure movie game…and nothing wrong with that. Do you want history or do you want Braveheart meets Robin Hood? It's fine to prefer the latter. You'll probably get more entertaining games and after all that's why we do it in the first place. Games that just consist of armoured cavalry knocking the living bleep out of each other can get a bit repetitive.

mtd and foot newly raised for a retinue that would not nessesarily have the lords livery?

Entirely depends on the specific period and how the troops were raised for service. There are too many options in that to provide a succinct answer. For example, circumstances in the WoTR were quite different to that in preceding centuries.

Most MAA serve the crown directly;

Certainly not true if you are talking about the WoTR. With earlier wars it might be partially true.

It's different in the WotR because there's competition for the crown itself and the structure of government. The WotR are the exception. After the WotR we're really getting beyond the the middle ages. Before that most MAA are serving for wages from the crown or because they are in capite tenants – a modest number have crown tenancies which, oddly are different beasts, but that's (proportionately) more common in Scotland. A quick look at pay rolls will show you what I mean.
OP, by mounted sergeants do you mean hobilars?

Sheriff being responsible for recruitment makes absolute sense, a similar legal proceeding that remains here in the US called posse commitus I suppose, at least in theory. War of the Roses 🌹 is a whole different tragic kettle of herring, so I'm not thinking beyond 1000-1350. Trying to stay in the chainmail only period to include the crusades. Historically the border wars between Scotland and England would be made at the "Kleine Krieg" level by a few men at arms and a number of mounted soldiers? So- the same situation would have so in the south as well as Wales?

Some 12th century English illustrations of shields:
Lust attacks Chastity with a Brand in Prudentius' Psychomachia, Cotton MS Titus D XVI, St Albans, England, 1120AD
Soldiers Attack Jerusalem, Bury Bible, Bury St Edmunds, England, c.1130-1135
Goliath in The Winchester Psalter or Psalter of Henry of Blois, Mid 12th century
The Winchester Bible, 12th century
Shields in the 'Guthlac Roll', England, c.1200

Druzhina
12th Century Illustrations of Costume & Soldiers

Kleine Kreig is a good way of putting it, but think in terms of MAA exclusively; there was no 'light cavalry' element. We know infantry were enlisted by sheriffs because we can see the various writs for service; it is an articulated system. A proportion of Scottish infantry were called out by earls because earls had a local government role in the same manner as we would find anywhere in N. Europe apart from England, where 'earl' is just a title after 1066. In essence, within his earldom the earl fulfils the role of the sheriffs in the rest of the country.
Was it the same in Wales? I could n't tell you, it's outwith my area of study.

Shields? What shields? link