You'd have to get properly into the nitty-gritty of everything before committing to that (as should anyone living together).
You'd also have to remember that it's generally not the big things that cause problems. You can agree on the big things beforehand, but it's then finding the ketchup in the fridge every bloody time when you think it should be kept in the cupboard that causes the insidious drip-drip of irritation.
Not exactly the same parenting style, no
That's your first major one. Big things you can generally hash out, but what about the peripheries.
Curfews and boundaries for older children for example? You can't get on a bit and discover that one will let an 8yo go to the park with friends and thinks 15yo's should come and go as they please where as the other insists on supervised playdates until 12.
Do you have similar takes on extra curricular activities (and finances for them)? Will half the kids be out at clubs every night, but the others once a week?
Christmases and birthdays - do you have the same ethos on presents? You can't have half the kids waking up to three presents and the others fifty three. Do you have the same take on Santa/Father Christmas?
Will you become default babysitters for each other? If so do you have the same kind of social life or does one like constant nights out and the other will end up being resentful?
When will your children get individual time with their parent? Will they ever get the chance to veg on the sofa with their Mum without another random around (that's often an issue in blended families)? Will every day out be all of you or will they be separate?
Financial wise - how will you each protect your homes financially if you are pooling finances and considered to be contributing to the others home?
How will you deal with repairs on each of the houses?
What if the tenants don't pay or she has to go down the eviction road? Will that be her expense or a unit expense?
What will be the plan if the setting breaks down as she won't be able to kick her tenants out right away so how will she and her children be protected from becoming homeless if you fall out, or if you die?
Do you have similar takes on shopping? It could easily get fractious if one is Heinz and brands and the other is Smart Price.
Meals - do you have the same take on children clearing/not having to clear their plate? All round the table or eat off knees?