This battle started in July 2008 when the Somali opposition fighters (Islamic Courts Union) ambushed an Ethiopian troop convoy. The scenario here starts theoretically just after that when the Ethiopians responded by sending a column supported by tanks and artillery South East to retake Beledweyne which had just fallen. The Islamic Courts Union et al had just taken Beledweyne as well as a number of other places uncontested.
On 5 July, there was fighting outside Bur-Gabo and the next day the Ethiopian forces approached Beledweyne and moved into Jandkundisho to prepare to an attack.
July 24, 2008 the Ethiopians attacked Beledweyne and moved in but the Islamic Courts Union counter attacked the next morning which was followed by a massive attack with artillery support.
After fighting continued for months around the town.
There was a lull before a large attack on until 16 August 2008 and then another attack on 11 September.
In November the Islamic Courts Union and the Ethiopians made a deal and the Ethiopians withdrew back across their border to the North.
I haven’t given the Ethiopians an entire Division, they appear to have about 4 with another in reserve, but two large brigade units of 7 infantry and a mechanised regiment which is the split described on Wikipedia which probably makes hake a division. They also have a tank brigade and artillery plus the troop convoy that was attacked at the start.
I really don’t know what the balance is.
In this scenario, I have given the Islamic Courts Union some motorised units which represents car and truck equipped infantry as you see on the news plus the artillery they were described as using.
Clearly these units would have been staggered and a lot would have happened over 5 months so it’s not ideal but it should give an idea.
The river is interesting as it actually divides the map so I put some Ethiopian forces West of the river assuming they crossed over further North. It does make Beledweyne quite formidable but im not sure that the river is generally that uncrossable, it might have plenty of bridges and even fords etc but the map only has 1 crossing at the moment
see Wikipedia Ethiopian Armed Forces