Re: Migration strategies
Thanks for the advice, you're right that it's easy to get cornered. In my first Ostrogoths campaign, outlying Roman cities were easy to plunder, for coin and to improve the loyalty (integrity) of my armies. I came under heavy attack from Eastern Rome, so I headed into the Western Roman Empire.
When I looted a city in northern Italy, a Western Roman secessionist faction emerged. This conflict between Western Rome and their secessionists looked like an opportunity, so I marched both of my armies into northern Italy, where they were slaughtered by six Roman armies which attacked in a single turn!
Your advice on managing a horde is helpful, yes I'm learning to set camp and to be cautious about new slots or new hordes. I also noticed that research seems to increase your Imperium even if you haven't recruited any additional armies.
I tried again as the Ostrogoths, taking a more northerly path to avoid Italy, but this time my two armies were destroyed by four Western Roman armies which attacked together. Despite these setbacks, I'm having fun with Attila. Your advice to try a different faction sounds good - maybe the Suebi, or perhaps a non-horde faction on the edge of the map somewhere, so I can learn some of the new game mechanics in a less dangerous area.