Vega Squadron support Semion "CeMaTheSlayeR" Krivulya shared his ideas about Tusk in the current meta.
- Tusk is not the strongest hero at the moment. He's decent but a bit weaker than meta-roamers. But since the team is young we're playing heroes that people know how to play. I have many games played on Tusk and we choose him. Other teams are using Monkey King and Earth Spirit for this purpose, but I don't really know how to play them on the right level. Tusk is a solid roamer with useful skills that can carry useful artifacts and doesn't have to farm Blink Dagger.
Generally speaking, if you want to pick a 4th position and don't possess any good choices then Tusk is a great option. As any hero, he makes good use of early kills but can still be useful without those. Even with level 5 on minute 15 he has perspectives and opportunities. Ice Shards and Sifil are useful in any situation if you use them right.
What goes to talents, on lvl 10 you pick experience bonus. This is the trick that gives him the opportunity compared to other heroes. If you got level 10 with good timings then the game will go smooth for you from this point on. If it happened later, you've got all the means to catch up quickly. On level 15 he has good talent for ball damage, on level 20 choices are average, but it gets better by 25. So, we receive a strong lategame herio that has HP artifacts, he's hard to burst down, he can save everyone in his ball, limits opponents' movement using Shards and cancels TP's through BKB's. By the way, starting at level 6 he has 2 stuns that is extremely useful.
Speaking about why teams are not picking Tusk so often, it's easy to explain as not many players are good with it. For example, JerAx and iceice have played a lot of games on it and it's being used. He's not that hard to play on, but without experience of playing on it you may turn out being useless in the game.
Winrate-wise this hero is not looking strong (45% on 5K+ MMR and lower on lower ratings) but that's mostly because pubs don't have much teamplay and team movement while all his skills are teamplay-oriented. He can play solo with Shadow Blade and Desolator and crit down supports with 1 hit but I don't know if it works now. I played on Tusk recently with such build and it didn't impress me. So, picking him in pubs is not recommended.