No it isn't. If the combined opposition(s) have more than you they can form a coalition government, and hey presto, you are the opposition, without power. Then you're 'win' disappears. It's happened often.
No because the party with the biggest share of the vote, which in turns means the biggest number of seats, is by rule allowed the first opportunity of forming a government. They can either do this, as Labour have done in Scotland, by forming a coalition. Or as the SNP choose to do in 2006 and 2016, they can form a minority government.
The opposition, can then, choose to block every policy of the minority government, if it wishes to do so. However, the simple fact is, that politicians are elected to serve. Opposing every move of an elected minority administration would lead to dead-lock and another election – an election in which the opposition would be decimated. That generally does not happen, as in Scotland’s case we have 5 main political parties (not 2 as in England) plus independents. There are always deals to be done.
What you are doing is basing your view on the Westminster system. We laugh in Scotland when English commentators talk about a hung parliament as if it is the end of the world.
Ms May herself as failed to understand her own position. English people are conditioned to the 4 or 5 year dictatorial government system. May failed to recognise that she was in fact running a minority administration (that is after throwing her majority away). To successfully run a minority administration, you have to work with the opposition to obtain consensus in order to govern.
What we are seeing is a failure of the first past the post system, and a political class that do not understand how to govern when it does not produce the result it is designed to produce.
The fact is that Scotland, like most of Europe, does not run a first past the post system. As such coalition and minority government is the norm, as is politicians working across party lines to deliver policy and change.