Complex sentence: The Qatar M-Sport World Rally Team became the de-facto lead team with returning Mads Østberg and Evgeny Novikov, while a separate formation-Qatar World Rally Team was also supported by M-Sport with drivers Al-Attiyah and Thierry Neuville.
Split into simpler sentences: The Qatar M-Sport World Rally Team became the de-facto lead team, with returning Mads Østberg and Evgeny Novikov. Meanwhile a separate formation-Qatar World Rally Team was also supported by M-Sport, with drivers Al-Attiyah and Thierry Neuville.