Complex sentence: The team hired 1999 world championship runner up Eddie Irvine to partner former Stewart driver Johnny Herbert, but the results that season did not match the results that Stewart had been able to achieve in 1999.
Split into simpler sentences: The team hired 1999 world championship runner up Eddie Irvine to partner former Stewart driver Johnny Herbert. The results that season did not match the results that Stewart had been able to achieve in 1999.