For those two games, just load that last C rom again and use the swapc flag.
// King of the Monsters 2
static struct BurnRomInfo kotm2RomDesc[] = {
{"039-p1.bin" , 0x080000, 0xb372d54c, 0x10}, // 0 68K code
{"039-p2.bin" , 0x080000, 0x28661afe, 0x10}, // 1
{"039-s1.bin" , 0x020000, 0x63ee053a, 1}, // 2 Text layer tiles
{"039-c1.bin" , 0x200000, 0x6d1c4aa9, 1}, // 3 Sprite data
{"039-c2.bin" , 0x200000, 0xf7b75337, 1}, // 4
{"039-c3.bin" , 0x080000, 0xbfc4f0b2, 1}, // 5
{"039-c4.bin" , 0x080000, 0x81c9c250, 1}, // 6
{"039-c4.bin" , 0x080000, 0x81c9c250, 1}, // 6
{"039-m1.bin" , 0x020000, 0x0c5b2ad5, 0x10}, // 7 Z80 code
{"039-v1.bin" , 0x200000, 0x86d34b25, 2}, // 8 Sound data
{"039-v2.bin" , 0x100000, 0x8fa62a0b, 2}, // 9
};
STDROMPICKEXT(kotm2, kotm2, neogeo);
STD_ROM_FN(kotm2);
struct BurnDriver BurnDrvKotm2 = {
{"kotm2", "King of the Monsters 2: The Next Thing", NULL, "SNK", "Neo Geo", "1992", NULL, "neogeo"},
BDF_GAME_WORKING, 2, HARDWARE_SNK_NEOGEO | HARDWARE_SNK_SWAPC,
NULL, kotm2RomInfo, kotm2RomName, neogeoInputInfo, neogeoDIPInfo,
NeoInit, NeoExit, NeoFrame, NeoRender, NeoScan, &NeoRecalcPalette,
nNeoScreenWidth, 224, 4, 3
};
// Sengoku 2
static struct BurnRomInfo sengoku2RomDesc[] = {
{"040-p1.bin" , 0x100000, 0x6dde02c2, 0x10}, // 0 68K code
{"040-s1.bin" , 0x020000, 0xcd9802a3, 1}, // 2 Text layer tiles
{"040-c1.bin" , 0x200000, 0xfaa8ea99, 1}, // 3 Sprite data
{"040-c2.bin" , 0x200000, 0x87d0ec65, 1}, // 4
{"040-c3.bin" , 0x080000, 0x24b5ba80, 1}, // 5
{"040-c4.bin" , 0x080000, 0x1c9e9930, 1}, // 6
{"040-c4.bin" , 0x080000, 0x1c9e9930, 1}, // 6
{"040-m1.bin" , 0x020000, 0xd4de4bca, 0x10}, // 7 Z80 code
{"040-v1.bin" , 0x200000, 0x71cb4b5d, 2}, // 8 Sound data
{"040-v2.bin" , 0x100000, 0xc5cece01, 2}, // 9
};
STDROMPICKEXT(sengoku2, sengoku2, neogeo);
STD_ROM_FN(sengoku2);
struct BurnDriver BurnDrvSengoku2 = {
{"sengoku2", "Sengoku 2", "Japanese title is Sengoku Denshou 2", "SNK", "Neo Geo", "1993", NULL, "neogeo"},
BDF_GAME_WORKING, 2, HARDWARE_SNK_NEOGEO | HARDWARE_SNK_SWAPC | HARDWARE_SNK_SWAPP | HARDWARE_SNK_NEOGEO,
NULL, sengoku2RomInfo, sengoku2RomName, neogeoInputInfo, neogeoDIPInfo,
NeoInit, NeoExit, NeoFrame, NeoRender, NeoScan, &NeoRecalcPalette,
nNeoScreenWidth, 224, 4, 3
};