I dont think its cheating, Sure it makes things alittle easier but who cares really.Without them you can have a team that dominates the BSN/BSS and with the addition of a few players next season dominate the BSP too.
Reunion players sell for a decent ammount for lower league clubs which i suppose makes funds for league 2 abit easier than not signing them but seeing as you dont pay a transfer fee for players until atleast league 1 i dont see that as a big problem, Just gives you abit more cash for wages nothing else.
I used them as Farsley and it was easy to dominate the BSN and BSP and even league 2.I havent used them on my Gateshead game and i actually did better in BSN BSP and league 2.
Use them dont use them really the difference they make is small.