Does the company have lots of expatriate employees or are you a one-off?
If they are used to sending employees abroad, they will have a policy and you can like it or lump it.
For school fees, it depends on the country. If it is foreign language, you can reasonably expect school fees to be paid. If it is English speaking, westernised, then they may well say that local schools are adequate, unless your children are in exam years and should really be in a British curriculum school.
What you get really depends on the company. When we moved to the US, the idea was for the assignment to be a smooth and burdenless as possible.
We got business class flights, plus a cash equivalent of business class fares for trips home each year for the whole family, and the transition weeks at full business expenses. Our housing in our host country was covered in full, including a generous allowance for bills. The size and neighbourhood was equivalent to similar status local employees (ie big). We were expected to rent out our house in the UK, but agent fees were reimbursed, and a guaranteed minimum should the house be empty. Our full household goods were transported by air and sea.
We had the services of a relocation agent who sorted out contracts, connected utilities, arranged schools, hire car, pick up from airport etc.
We had expatriate medical insurance which was very good.
Salary was the UK one with a 10% foreign service premium, plus a $10k per year spouse hobby fund. We had interest free loans for cars and appliances, and had a minimum depreciation at the end of the assignment. Taxes were prepared for the duration of the assignment plus the two transition years, and taxes with full tax equalisation.
Our cats were transported there and back, and UK quarantine covered in full on our return.
But we did have to use local schools.