The easiest way forward is:
1. charter a car + driver from Tana to Toliara and take a flight back to Tana (or the other way around). It will be easier to find a car + driver than to try and rent yourself, and the driver will drive back to Tana.
2. charter a car + driver from Tana to Mahajunga and take a flight back to Tana... So exactly the same as toward Toliara. You have your best chances for Mad. Pratincole (supposed you don't go to Masoala) and Mad. Harrier (supposed you don't go to Bemenavika, and you have a lower chance between Anja Reserve and Isalo in the South) on that stretch, so I'd consider it a must-do.
For both 1. and 2., you can charter the car + driver to visit Andasibe / Mantadia (going back and forth between Tana and Andasibe).
I haven't been to Tolagnaro, but unless you're really after Red-tailed Newtonia and you're looking for a new site for Yellow-bellied Sunbird-Asity, I wonder why you wouldn't fly to e.g. Masoala (so you have a very good chance to see Helmeted Vanga)?
If you want to inquire about chartering vehicles, I can recommend contacting Alain at :
Colourful Natures - Onvergetelijke reizen in Madagaskar
He lives part of the year in Madagascar and can arrange everything + he's someone I would trust a 100%