Greetings,

unfortunately, I cannot say much for British Indian Army units that fought in the North African Campaign since my area of expertise is on the Malayan Campaign. The difference between units in the two theatres is that more experienced sepoys and units were sent to North Africa since that theatre was opened earlier. To my knowledge, there is no major difference between the two but more seasoned sepoys within the army tend to know better basic English if any at all thus making command between them and European officers less problematic. On the other hand, the Malayan Campaign and later Burma Campaign saw the use of many recently levied sepoys that were little more than boys with some bare-bones military training so communications were much more of a problem.

My discussion will largely be at the Battalion and Company level since any higher than that the commanders and their staff were largely European or highly educated and English speaking Indians. The Officers within the unit were both British and Indian and were either King Commissioned Officers (KCO) or Viceroy Commissioned Officers (VCO). The KCOs were almost exclusively European and as the name implies had their commission as officers given by the King. VCOs, on the other hand, were both European and Indian and had their commission given to them by the Viceroy of India. In terms of leadership ability, there was not necessarily a difference since most Indian VCOs graduated from the Indian Military Academy and in some cases were better than European Officers that were commissioned directly from civilians since they received lengthy training as career soldiers. These officers spoke English and normally Hindi but depending on their ethnicity and unit they were assigned to spoke their mother tongue which could range from Tamil to Urdu to Bengali to name a few. Seasoned career European officers also picked up the native language of their unit and had at least a rudimentary proficiency in this but this was not always the case. For the Malayan Campaign, the Indian Army Divisions sent there were comprised only partially of regular officers and the rest were recently commission European civilians. They generally could not speak the language with a few exceptions since the officers were frequently drawn from foremen or managers which had to work with the locals.

Next were the Non-Commission Officers (NCO) which were the next rung of commanders within the Army. Sergeants were referred to as Havildar and Corporals as Naik and formed the backbone of the Indian Army as the main line of communication between the officers and the troops. NCOs within the army were all Indian and thus spoke their own language and were generally able to speak a decent level of English since they were career soldiers and had a good few years of service under their belt allowing them to pick it up. Most British officers, even those that had some level of proficiency with the language, were unable to relay complex instructions or hold any conversation at length with the sepoys. Thus they normally relied on their NCOs and especially their Havildar that had an adequate proficiency in both languages to coordinate their section to carry out tactics more complex than simple instructions such as advancing and halt. The British officers also did not fraternize with the men and thus Havidars were generally relied upon to interact with them on a day to day basis and provided relatable role models for the men.

Sepoys were the catch all term used by the British for their men and generally spoke little to no English. More experienced sepoys that had served longer had a rudementary understanding of English. For the units in the Malayan Campaign as stated above they were comprised of farm boys barely old enough to be conscripted and thus had no proficiency in English at all. Thus the units functionally had to rely upon their experienced Havildar to relay commands and instructions to them from their officers unless they were fortunate enough to have an Indian officer. Translators for field units were thus non-existent since NCOs effectively acted as this and all-ranks gradually picked up both English and the native language of the unit.

Units were organised along ethnic and religious lines so as to streamline communications and logistics. Rations varied from unit to unit depending on things such as religion which changed their dietary requirements and their region which changed their preference. I apologise again since the sources I use do not go into detail on what rations they consumed but suffice to say it was a real hassle to manage. Later on in the Malayan Campaign when units from different regions amalgamated, the logistics for them was a nightmare which exacerbated racial tensions. The logistics corps had to provide the same battalion and in a lot of instances the same Coy with both Halal food and food for Hindus which was difficult, to say the least.

Sources:

Singapore Burning: Heroism and Surrender in WWII - Colin Smith

The Defense and Fall of Singapore - Brian P. Farrell