not sure bout the rivalry bit my dog is 9 months got him when he was 6 wks he is family/working dog and lives with 2 cats! in all honesty he doesnt smell and kennels are jus one more room to clean and im defo considering another!!
depends on how old they are and what they have been living in jus like your 2 if they av been indoors they cani go outdoors an if theve been kenneled chances r they aint gonna be house trained