Please read my comment below for the article.
For your question you must have to see not through the lens of a unified Hong Kong. Hong Kong is really international.
Firstly, there are four - June 9 1m+ then jun 9 evening; June 12 with some conflict but mostly the young one trying to stop the bill without this the bill would not have even suspended; jun 16 the 2m+. their composition are very different. The target is also different.
My comment and the article hopefully give you some hint on the jun 9 and jun 12 1 and 2m+. They are across spectrum of whole Hong Kong.
May I roughly said 1/2 of hker have foreign passport or at least have relatives overseas. Many of the protestors are not want to go but do have a place to go. Or try hard to. You may note those hongkonges’ link as 29 cities around the world join the protest. That segment join not to emigrate as they did it already. The law affected them staying in Hong Kong. But more importantly they would affect the Hong Kong status as it affect the foreigner as well.
You have to aware many of the objection to the law are coming from official diplomatic with official letters from Eu, Britain and many different USA camp. The 85,000 American lived here is a force. There are foreigners in the protest. If they go, Hongkong is done.
(There are another group. About 1m of hker are not really hker. They just come in the last 20 years for various reasons. The huawei woman in Canada is holding 3 hk passport. I suspect they might not have join the protest as they conf to hk to hide etc. Now they trigger others as if these group go the property markets may die. Hk is the most expensive place in the world to own a car park size flat. Other then foreigner these affect is key.)
This 2m+ protest is very unusual as many are pro-china and pro-establishment camp. For this they will no doubt stay. But it is driving away foreigner and hidden chinese rich that would affect them.
Guess you are after the two major protest but the conflict one. We are not sure about the brick throwing etc. But quite sure many of the protestor as reported by those hymns signing Christian are young kids. They call hk home. They would fight by putting their body between the gun and the legislature chamber to prevent the bill to pass. They are less calculated than we adults. They saw this as a beginning of end of Hong Kong as the chinese law come to rule. At all cost they have to stop it.
One protestor said clearly “shoot me dead is better than this” and then she join the effort encircling the chamber. Many young one was hurt as there is no weapon. One of my friend trying to help found out first time it hurt a lot when tear gas residue touch your skin. And she is just helping. But whilst crying and painful our kids just wash their eyes and skins. And go back. One said “I do not want to give up”. All still lost as the chamber finally was cleared. In fact they will charge 7-10 year in jail if caught. (And if they had gone to Hosiptal and without the doctor and nurse reporting them somehow the police know. Two get arrested this way.)
But the story leaked out to us all. Unlike umbrella movement there is no leader. None. Just kids organised themselves using telegram where to go. It was a shock to oldies like us. Self organised ... no match to riot police. But just kids fighting for their home.
The community know and shock. That is why one of the slogan is to not to define this as riot and release the student involved. In the protest sometimes I can see parents walking not very normal protestor like. Then I saw a boy or a girl around. You can sense what is going on. I suspect they come is to ensure the kid not to do this alone. May be they drag them out if something happen.
Before I went to protest one of my neigbour looking at me wearing black t shirt. They said they would not go themselves. But they told a bit their family and relatives story. It is like everyone know someone’s kid are involved. As she said in the past she blamed the activist. But all in jail now. These kids just went themselves. They are nice kids not troublemaker they said. Help them is their message if they are pro government.
These kids are not going to go anywhere. Better die than run, unlike their parents like us. Hong Kong is their home. 2047. I do not see they see there is a deadline. It is their motherland. Hong Kong is not China. Hong Kong is Hong Kong.
Hence even shocking to us usual protestor, the whole community move to protect their kids. I never saw so many people in my life m. I have even joined the jun 9 million people protest and June 16 is a totally different scale.
Not sure I answer your question as I do not know what are their strategy, tactics or plan. but I hope I give you an impression as one protestor following the case. It is a shock. If we live long enough you will see either a tragedy or a birth of a nation. God bless.